diff --git a/src/main/java/cn/kastner/oj/controller/ContestRestController.java b/src/main/java/cn/kastner/oj/controller/ContestRestController.java
index fe6417c..c0061eb 100644
--- a/src/main/java/cn/kastner/oj/controller/ContestRestController.java
+++ b/src/main/java/cn/kastner/oj/controller/ContestRestController.java
@@ -8,6 +8,7 @@
 import cn.kastner.oj.query.ContestQuery;
 import cn.kastner.oj.query.RankingQuery;
 import cn.kastner.oj.service.ContestService;
+import org.apache.poi.ss.usermodel.Workbook;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.access.prepost.PreAuthorize;
@@ -15,6 +16,9 @@
 import org.springframework.validation.annotation.Validated;
 import org.springframework.web.bind.annotation.*;
 
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.io.OutputStream;
 import java.util.List;
 
 @RestController
@@ -167,6 +171,23 @@ public RankingDTO getRanking(@PathVariable String id, RankingQuery query) throws
     return contestService.getRanking(id, query);
   }
 
+  @GetMapping("/{id}/ranking/export")
+  public void exportRanking(
+      @PathVariable String id, RankingQuery query, HttpServletResponse response)
+      throws ContestException {
+    response.setHeader("content-type", "application/octet-stream");
+    response.setContentType("application/octet-stream");
+    String fileName = contestService.findById(id).getName() + "排名";
+    response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
+
+    Workbook workbook = contestService.exportRanking(id, query);
+    try (OutputStream os = response.getOutputStream()) {
+      workbook.write(os);
+    } catch (IOException e) {
+      throw new ContestException(ContestException.EXPORT_ERROR);
+    }
+  }
+
   @PatchMapping("/{id}/status")
   @PreAuthorize("hasAnyRole('ADMIN', 'STUFF')")
   public ContestDTO setContestStatus(@PathVariable String id, @RequestParam ContestOption option)
diff --git a/src/main/java/cn/kastner/oj/domain/ContestProblem.java b/src/main/java/cn/kastner/oj/domain/ContestProblem.java
index 50ed43b..aa314a8 100644
--- a/src/main/java/cn/kastner/oj/domain/ContestProblem.java
+++ b/src/main/java/cn/kastner/oj/domain/ContestProblem.java
@@ -44,7 +44,7 @@ public class ContestProblem {
   @Transient
   private List<TimeCost> timeList = new ArrayList<>();
 
-  @OneToOne
+  @OneToOne(fetch = FetchType.LAZY)
   @NotFound(action = NotFoundAction.IGNORE)
   private Submission firstSubmission;
 
diff --git a/src/main/java/cn/kastner/oj/domain/RankingUser.java b/src/main/java/cn/kastner/oj/domain/RankingUser.java
index fce38ea..ed2fd51 100644
--- a/src/main/java/cn/kastner/oj/domain/RankingUser.java
+++ b/src/main/java/cn/kastner/oj/domain/RankingUser.java
@@ -42,7 +42,7 @@ public class RankingUser {
 
   private Long time = 0L;
 
-  @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "rankingUser")
+  @OneToMany(fetch = FetchType.EAGER, mappedBy = "rankingUser")
   @Fetch(FetchMode.SUBSELECT)
   @OrderBy("id DESC ")
   @JsonIgnore
diff --git a/src/main/java/cn/kastner/oj/domain/TimeCost.java b/src/main/java/cn/kastner/oj/domain/TimeCost.java
index 21c5eb5..192d49c 100644
--- a/src/main/java/cn/kastner/oj/domain/TimeCost.java
+++ b/src/main/java/cn/kastner/oj/domain/TimeCost.java
@@ -16,7 +16,7 @@ public class TimeCost {
   @Column(length = 40)
   private String id = UUID.randomUUID().toString();
 
-  @ManyToOne
+  @ManyToOne(fetch = FetchType.LAZY)
   @NotFound(action = NotFoundAction.IGNORE)
   private ContestProblem contestProblem;
 
@@ -30,11 +30,9 @@ public class TimeCost {
 
   private Boolean firstPassed = false;
 
-  private Boolean frozen = false;
-
   private Double score = 0.0;
 
-  @ManyToOne
+  @ManyToOne(fetch = FetchType.LAZY)
   @NotFound(action = NotFoundAction.IGNORE)
   private RankingUser rankingUser;
 
diff --git a/src/main/java/cn/kastner/oj/exception/ContestException.java b/src/main/java/cn/kastner/oj/exception/ContestException.java
index 312cd30..1853c26 100644
--- a/src/main/java/cn/kastner/oj/exception/ContestException.java
+++ b/src/main/java/cn/kastner/oj/exception/ContestException.java
@@ -34,6 +34,8 @@ public class ContestException extends AppException {
 
   public static final String BAD_CONTEST_STATUS = "不合法的比赛状态";
 
+  public static final String EXPORT_ERROR = "导出错误";
+
   public ContestException(String message) {
     super(message);
     switch (message) {
@@ -97,6 +99,10 @@ public ContestException(String message) {
         this.code = -16;
         this.status = HttpStatus.FORBIDDEN;
         break;
+      case EXPORT_ERROR:
+        this.code = -17;
+        this.status = HttpStatus.INTERNAL_SERVER_ERROR;
+        break;
       default:
         this.code = -1;
         this.status = HttpStatus.INTERNAL_SERVER_ERROR;
diff --git a/src/main/java/cn/kastner/oj/factory/RankingUserFactory.java b/src/main/java/cn/kastner/oj/factory/RankingUserFactory.java
index 0f8f0b7..0157183 100644
--- a/src/main/java/cn/kastner/oj/factory/RankingUserFactory.java
+++ b/src/main/java/cn/kastner/oj/factory/RankingUserFactory.java
@@ -29,7 +29,6 @@ public static RankingUser create(User user, Contest contest, Group group) {
       TimeCost timeCost = new TimeCost();
       timeCost.setContestProblem(contestProblem);
       timeCost.setRankingUser(rankingUser);
-      timeCost.setFrozen(false);
       timeCostList.add(timeCost);
     }
     rankingUser.setTimeList(timeCostList);
diff --git a/src/main/java/cn/kastner/oj/repository/ContestProblemRepository.java b/src/main/java/cn/kastner/oj/repository/ContestProblemRepository.java
index 4d308e5..ebfeae9 100644
--- a/src/main/java/cn/kastner/oj/repository/ContestProblemRepository.java
+++ b/src/main/java/cn/kastner/oj/repository/ContestProblemRepository.java
@@ -21,4 +21,6 @@ public interface ContestProblemRepository
   void deleteAllByProblemAndContest(Iterable<Problem> problems, Contest contest);
 
   void deleteAllByContest(Contest contest);
+
+  Integer countByContest(Contest contest);
 }
diff --git a/src/main/java/cn/kastner/oj/service/ContestService.java b/src/main/java/cn/kastner/oj/service/ContestService.java
index 2c3a2d5..b9fc508 100644
--- a/src/main/java/cn/kastner/oj/service/ContestService.java
+++ b/src/main/java/cn/kastner/oj/service/ContestService.java
@@ -6,6 +6,7 @@
 import cn.kastner.oj.exception.ProblemException;
 import cn.kastner.oj.query.ContestQuery;
 import cn.kastner.oj.query.RankingQuery;
+import org.apache.poi.ss.usermodel.Workbook;
 
 import java.util.List;
 
@@ -49,4 +50,6 @@ void deleteProblems(List<String> problemIdList, String contestId)
   void joinContest(String id, String password) throws ContestException;
 
   RankingDTO getRanking(String id, RankingQuery query) throws ContestException;
+
+  Workbook exportRanking(String id, RankingQuery query) throws ContestException;
 }
diff --git a/src/main/java/cn/kastner/oj/service/impl/ContestServiceImpl.java b/src/main/java/cn/kastner/oj/service/impl/ContestServiceImpl.java
index 5a01552..df9fe4e 100644
--- a/src/main/java/cn/kastner/oj/service/impl/ContestServiceImpl.java
+++ b/src/main/java/cn/kastner/oj/service/impl/ContestServiceImpl.java
@@ -17,6 +17,10 @@
 import cn.kastner.oj.service.ContestService;
 import cn.kastner.oj.util.CommonUtil;
 import cn.kastner.oj.util.DTOMapper;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.xssf.usermodel.XSSFSheet;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
@@ -243,7 +247,9 @@ public List<RankingUserDTO> addUsersByGroups(List<String> groupIdList, String co
     for (Group group : groupList) {
       for (User user : group.getUserSet()) {
         if (!userSet.contains(user)) {
-          addRankingUserList.add(RankingUserFactory.create(user, contest, group));
+          RankingUser rankingUser = RankingUserFactory.create(user, contest, group);
+          timeCostRepository.saveAll(rankingUser.getTimeList());
+          addRankingUserList.add(rankingUser);
         }
       }
     }
@@ -387,7 +393,6 @@ public List<ProblemDTO> addProblems(List<String> problemIdList, String contestId
           TimeCost timeCost = new TimeCost();
           timeCost.setContestProblem(contestProblem);
           timeCost.setRankingUser(rankingUser);
-          timeCost.setFrozen(true);
           addTimeCostList.add(timeCost);
         }
 
@@ -436,7 +441,6 @@ public void addProblem(String problemId, String contestId, Integer score)
         TimeCost timeCost = new TimeCost();
         timeCost.setContestProblem(contestProblem);
         timeCost.setRankingUser(rankingUser);
-        timeCost.setFrozen(true);
 
         addTimeCostList.add(timeCost);
 
@@ -606,20 +610,13 @@ public RankingDTO getRanking(String id, RankingQuery query) throws ContestExcept
       return rankingDTO;
     } else if (contest.getStatus() == ContestStatus.ENDED) {
       Set<RankingUser> rankingUserList = rankingUserRepository.findByContest(contest);
+
+      if (!rankingUserList.isEmpty()) {
+        rankingUserList = filterWithQuery(rankingUserList, query);
+      }
       for (RankingUser ru : rankingUserList) {
         ru.setTimeList(timeCostRepository.findByRankingUser(ru));
       }
-      if (!rankingUserList.isEmpty()) {
-        if (null != query.getGroupId()) {
-          rankingUserList = rankingUserList.stream().filter(
-              rankingUserDTO -> query.getGroupId().equals(rankingUserDTO.getGroupId())
-          ).collect(Collectors.toSet());
-        } else if (null != query.getTeacherId()) {
-          rankingUserList = rankingUserList.stream().filter(
-              rankingUserDTO -> query.getTeacherId().equals(rankingUserDTO.getTeacherId())
-          ).collect(Collectors.toSet());
-        }
-      }
       contest.setRankingUserList(rankingUserList);
       return mapper.contestToRankingDTO(contest);
     } else {
@@ -628,6 +625,85 @@ public RankingDTO getRanking(String id, RankingQuery query) throws ContestExcept
 
   }
 
+  private Set<RankingUser> filterWithQuery(
+      Set<RankingUser> rankingUserList, RankingQuery query) {
+    if (null != query.getGroupId()) {
+      return rankingUserList.stream().filter(
+          rankingUserDTO -> query.getGroupId().equals(rankingUserDTO.getGroupId())
+      ).collect(Collectors.toSet());
+    } else if (null != query.getTeacherId()) {
+      return rankingUserList.stream().filter(
+          rankingUserDTO -> query.getTeacherId().equals(rankingUserDTO.getTeacherId())
+      ).collect(Collectors.toSet());
+    }
+    return rankingUserList;
+  }
+
+  @Override
+  public Workbook exportRanking(String id, RankingQuery query) throws ContestException {
+    Contest contest =
+        contestRepository
+            .findById(id)
+            .orElseThrow(() -> new ContestException(ContestException.NO_SUCH_CONTEST));
+    Set<RankingUser> rankingUserSet = rankingUserRepository.findByContest(contest);
+    rankingUserSet = filterWithQuery(rankingUserSet, query);
+    XSSFWorkbook workbook = new XSSFWorkbook();
+    XSSFSheet sheet = workbook.createSheet("排名信息");
+
+    int rowNum = 0;
+    Row header = sheet.createRow(rowNum++);
+    int headerColumnNum = 0;
+    header.createCell(headerColumnNum++).setCellValue("排名");
+    header.createCell(headerColumnNum++).setCellValue("学号");
+    header.createCell(headerColumnNum++).setCellValue("姓名");
+    if (contest.getJudgeType() == JudgeType.IMMEDIATELY) {
+      header.createCell(headerColumnNum++).setCellValue("提交数");
+      header.createCell(headerColumnNum++).setCellValue("通过数");
+    } else {
+      header.createCell(headerColumnNum++).setCellValue("总分");
+    }
+    header.createCell(headerColumnNum++).setCellValue("指导教师");
+    header.createCell(headerColumnNum++).setCellValue("小组/班级");
+    for (int i = 'A', j = 0; j < contestProblemRepository.countByContest(contest); i++, j++) {
+      header.createCell(headerColumnNum++).setCellValue(String.format("%c", i));
+    }
+
+    for (RankingUser rankingUser : rankingUserSet) {
+      Row row = sheet.createRow(rowNum++);
+      int columnNum = 0;
+      row.createCell(columnNum++).setCellValue(rankingUser.getRankingNumber());
+      row.createCell(columnNum++).setCellValue(rankingUser.getUser().getStudentNumber());
+      row.createCell(columnNum++).setCellValue(rankingUser.getUser().getName());
+      if (contest.getJudgeType() == JudgeType.IMMEDIATELY) {
+        row.createCell(columnNum++).setCellValue(rankingUser.getAcceptCount());
+        row.createCell(columnNum++).setCellValue(rankingUser.getSubmitCount());
+      } else {
+        row.createCell(columnNum++).setCellValue(rankingUser.getScore());
+      }
+      Optional<User> teacherOptional = userRepository.findById(rankingUser.getTeacherId());
+      if (teacherOptional.isPresent()) {
+        row.createCell(columnNum++).setCellValue(teacherOptional.get().getName());
+      } else {
+        columnNum++;
+      }
+      Optional<Group> groupOptional = groupRepository.findById(rankingUser.getGroupId());
+      if (groupOptional.isPresent()) {
+        row.createCell(columnNum++).setCellValue(groupOptional.get().getName());
+      } else {
+        columnNum++;
+      }
+      List<TimeCost> timeCostList = timeCostRepository.findByRankingUser(rankingUser);
+      for (TimeCost timeCost : timeCostList) {
+        if (contest.getJudgeType() == JudgeType.IMMEDIATELY) {
+          row.createCell(columnNum++).setCellValue(timeCost.getPassed() ? 1 : 0);
+        } else {
+          row.createCell(columnNum++).setCellValue(timeCost.getScore());
+        }
+      }
+    }
+    return workbook;
+  }
+
   private void requirePassword(Contest contest) throws ContestException {
     if (ContestType.SECRET_WITH_PASSWORD.equals(contest.getContestType())
         && contest.getPassword() == null) {
diff --git a/src/main/java/cn/kastner/oj/task/RankingComputingTask.java b/src/main/java/cn/kastner/oj/task/RankingComputingTask.java
index c9169c2..585e030 100644
--- a/src/main/java/cn/kastner/oj/task/RankingComputingTask.java
+++ b/src/main/java/cn/kastner/oj/task/RankingComputingTask.java
@@ -60,7 +60,7 @@ public void computeRank() {
           i--;
         }
       }
-      redisTemplate.opsForValue().set("rankingUserList:" + contest.getId(), mapper.toRankingUserDTOs(rankingUserList));
+      redisTemplate.opsForValue().set("rankingUserList:" + contest.getId(), mapper.toRankingUserDTOs(rankingUserRepository.saveAll(rankingUserList)));
     }
   }
 }