diff --git a/YD_Event.Application/Event/JudgeAssignmentService.cs b/YD_Event.Application/Event/JudgeAssignmentService.cs
index 5cdf0fa..79f75c6 100644
--- a/YD_Event.Application/Event/JudgeAssignmentService.cs
+++ b/YD_Event.Application/Event/JudgeAssignmentService.cs
@@ -240,22 +240,74 @@ public class JudgeAssignmentService : IDynamicApiController, ITransient
             .ToList();
         var assignmentUnitSessionIds = assignmentUnitSessions.Select(x => x.Id).ToList();
 
-        // 赛前允许反复修改已提交的分配。保存新版本后先回到草稿态，重新提交后裁判端才可见。
-        await _assignmentRepository.SoftDeleteAsync(x => assignmentUnitSessionIds.Contains(x.SessionId) && x.AssignmentStatus < 9);
+        // 数据库可能仍使用不带软删除过滤条件的旧唯一索引 (SessionId, JudgeRole)。
+        // 因此反复保存同一席位时复用原记录，不能软删除后再插入相同键。
+        var existingAssignments = await _assignmentRepository.AsQueryable().ClearFilter()
+            .Where(x => assignmentUnitSessionIds.Contains(x.SessionId))
+            .ToListAsync();
+        var existingBySeat = existingAssignments
+            .GroupBy(x => $"{x.SessionId}:{x.JudgeRole}", StringComparer.OrdinalIgnoreCase)
+            .ToDictionary(group => group.Key,
+                group => group.OrderBy(x => x.DeleteMark)
+                    .ThenBy(x => x.Status != AvailabilityStatus.Enable)
+                    .ThenByDescending(x => x.CreatedTime).First(),
+                StringComparer.OrdinalIgnoreCase);
         var now = DateTime.Now;
         var refereeIds = seats.Select(x => x.Candidate.RefereeId).Distinct().ToList();
         var refereeUsers = (await _refereeRepository.AsQueryable()
             .Where(x => refereeIds.Contains(x.Id)).ToListAsync())
             .ToDictionary(x => x.Id, x => x.AppUserId);
-        var newAssignments = assignmentUnitSessions.SelectMany(sessionItem => seats.Select(x => new EventJudgeAssignment
+        var retainedIds = new HashSet<long>();
+        var updatedAssignments = new List<EventJudgeAssignment>();
+        var newAssignments = new List<EventJudgeAssignment>();
+        foreach (var sessionItem in assignmentUnitSessions)
         {
-            Id = _idGenerator.NextId(), EventId = input.EventId, SessionId = sessionItem.Id,
-            EventRefereeId = x.Candidate.EventRefereeId, RefereeId = x.Candidate.RefereeId,
-            JudgeUserId = refereeUsers.GetValueOrDefault(x.Candidate.RefereeId),
-            JudgeRole = x.SeatCode, JudgeRoleType = x.Slot.Code, AssignmentStatus = 0,
-            Status = AvailabilityStatus.Enable, CreatedUserId = _authManager.UserId, CreatedTime = now
-        })).ToList();
-        await _assignmentRepository.InsertRangeAsync(newAssignments);
+            foreach (var seat in seats)
+            {
+                var key = $"{sessionItem.Id}:{seat.SeatCode}";
+                if (existingBySeat.TryGetValue(key, out var assignment))
+                {
+                    retainedIds.Add(assignment.Id);
+                    assignment.EventRefereeId = seat.Candidate.EventRefereeId;
+                    assignment.RefereeId = seat.Candidate.RefereeId;
+                    assignment.JudgeUserId = refereeUsers.GetValueOrDefault(seat.Candidate.RefereeId);
+                    assignment.JudgeRole = seat.SeatCode;
+                    assignment.JudgeRoleType = seat.Slot.Code;
+                    assignment.AssignmentStatus = 0;
+                    assignment.SubmittedTime = null;
+                    assignment.Status = AvailabilityStatus.Enable;
+                    assignment.DeleteMark = false;
+                    assignment.UpdatedUserId = _authManager.UserId;
+                    assignment.UpdatedTime = now;
+                    updatedAssignments.Add(assignment);
+                }
+                else
+                {
+                    newAssignments.Add(new EventJudgeAssignment
+                    {
+                        Id = _idGenerator.NextId(), EventId = input.EventId, SessionId = sessionItem.Id,
+                        EventRefereeId = seat.Candidate.EventRefereeId, RefereeId = seat.Candidate.RefereeId,
+                        JudgeUserId = refereeUsers.GetValueOrDefault(seat.Candidate.RefereeId),
+                        JudgeRole = seat.SeatCode, JudgeRoleType = seat.Slot.Code, AssignmentStatus = 0,
+                        Status = AvailabilityStatus.Enable, CreatedUserId = _authManager.UserId, CreatedTime = now
+                    });
+                }
+            }
+        }
+
+        var removedAssignments = existingAssignments
+            .Where(x => !x.DeleteMark && !retainedIds.Contains(x.Id) && x.AssignmentStatus < 9)
+            .ToList();
+        removedAssignments.ForEach(assignment =>
+        {
+            assignment.DeleteMark = true;
+            assignment.AssignmentStatus = 9;
+            assignment.UpdatedUserId = _authManager.UserId;
+            assignment.UpdatedTime = now;
+        });
+        if (removedAssignments.Count > 0) await _assignmentRepository.UpdateRangeAsync(removedAssignments);
+        if (updatedAssignments.Count > 0) await _assignmentRepository.UpdateRangeAsync(updatedAssignments);
+        if (newAssignments.Count > 0) await _assignmentRepository.InsertRangeAsync(newAssignments);
     }
 
     /// <summary>