diff --git a/src/main/java/com/biutag/supervision/flow/action/ConfirmationCompletionAction.java b/src/main/java/com/biutag/supervision/flow/action/ConfirmationCompletionAction.java
index 0d33468..cbfc839 100644
--- a/src/main/java/com/biutag/supervision/flow/action/ConfirmationCompletionAction.java
+++ b/src/main/java/com/biutag/supervision/flow/action/ConfirmationCompletionAction.java
@@ -101,13 +101,14 @@ public class ConfirmationCompletionAction implements Action {
     public void updateNegative(String negativeId, ConfirmationCompletionData completionData) {
         Negative negative = negativeService.getById(negativeId);
         LocalDateTime now = LocalDateTime.now();
-        Long firstApproveTime = negative.getFirstApproveTime() == null ? 0L : negative.getFirstApproveTime();
-        if (negative.getLatestProcessTime() != null) {
-            firstApproveTime = firstApproveTime + TimeUtil.calculateWorkdayDuration(negative.getLatestProcessTime(), now);
+        Long firstApproveTime = negative.getFirstApproveTime();
+        // 覆盖制：每次重新计算，超时锁定则不更新
+        if (TimeUtil.canUpdateApproveTime(firstApproveTime) && negative.getLatestProcessTime() != null) {
+            firstApproveTime = TimeUtil.calculateWorkdayDuration(negative.getLatestProcessTime(), now);
         }
-        Long secondApprovalTime = negative.getSecondApprovalTime() == null ? 0L : negative.getSecondApprovalTime();
-        if (negative.getLatestProcessTime() != null) {
-            secondApprovalTime = secondApprovalTime + TimeUtil.calculateWorkdayDuration(negative.getLatestProcessTime(), now);
+        Long secondApprovalTime = negative.getSecondApprovalTime();
+        if (TimeUtil.canUpdateApproveTime(secondApprovalTime) && negative.getLatestProcessTime() != null) {
+            secondApprovalTime = TimeUtil.calculateWorkdayDuration(negative.getLatestProcessTime(), now);
         }
         LambdaUpdateWrapper<Negative> updateWrapper = new LambdaUpdateWrapper<Negative>()
                 .eq(Negative::getId, negativeId)
@@ -120,10 +121,16 @@ public class ConfirmationCompletionAction implements Action {
                 .set(Negative::getFlowKey, FlowNodeEnum.COMPLETED.getKey())
                 .set(Negative::getUpdTime, LocalDateTime.now());
         if ("2".equals(negative.getApprovalFlow())){
-            updateWrapper.set(Negative::getSecondApprovalTime, secondApprovalTime);
+            // 超时锁定时，不更新审批时长字段
+            if (TimeUtil.canUpdateApproveTime(secondApprovalTime)) {
+                updateWrapper.set(Negative::getSecondApprovalTime, secondApprovalTime);
+            }
         }
         if ("3".equals(negative.getApprovalFlow())){
-            updateWrapper.set(Negative::getFirstApproveTime, firstApproveTime);
+            // 超时锁定时，不更新审批时长字段
+            if (TimeUtil.canUpdateApproveTime(firstApproveTime)) {
+                updateWrapper.set(Negative::getFirstApproveTime, firstApproveTime);
+            }
         }
         negativeService.update(updateWrapper);
     }
diff --git a/src/main/java/com/biutag/supervision/flow/action/FirstApproveReturnAction.java b/src/main/java/com/biutag/supervision/flow/action/FirstApproveReturnAction.java
index 85d220b..ae54e5c 100644
--- a/src/main/java/com/biutag/supervision/flow/action/FirstApproveReturnAction.java
+++ b/src/main/java/com/biutag/supervision/flow/action/FirstApproveReturnAction.java
@@ -46,9 +46,10 @@ public class FirstApproveReturnAction implements Action {
     public void updateNegative(String negativeId, String nextFlowKey) {
         Negative negative = negativeService.getById(negativeId);
         LocalDateTime now = LocalDateTime.now();
-        Long firstApproveTime = negative.getFirstApproveTime() == null ? 0L : negative.getFirstApproveTime();
-        if (negative.getLatestProcessTime() != null) {
-            firstApproveTime = firstApproveTime + TimeUtil.calculateWorkdayDuration(negative.getLatestProcessTime(), now);
+        Long firstApproveTime = negative.getFirstApproveTime();
+        // 覆盖制：每次重新计算，超时锁定则不更新
+        if (TimeUtil.canUpdateApproveTime(firstApproveTime) && negative.getLatestProcessTime() != null) {
+            firstApproveTime = TimeUtil.calculateWorkdayDuration(negative.getLatestProcessTime(), now);
         }
         negativeService.update(new LambdaUpdateWrapper<Negative>()
                 .set(Negative::getFlowKey, negative.getIsSecondHandle() ? FlowNodeEnum.VERIFY.getKey() : nextFlowKey)
@@ -56,7 +57,7 @@ public class FirstApproveReturnAction implements Action {
                 // 当前处理对象
                 .set(Negative::getCurrentProcessingObject, String.format("%s专班", negative.getHandleSecondDepartName()))
                 .eq(Negative::getId, negativeId)
-                .set(Negative::getFirstApproveTime, firstApproveTime)
+                .set(TimeUtil.canUpdateApproveTime(firstApproveTime), Negative::getFirstApproveTime, firstApproveTime)
                 .set(Negative::getLatestProcessTime, now));
     }
 
diff --git a/src/main/java/com/biutag/supervision/flow/action/SecondApproveAction.java b/src/main/java/com/biutag/supervision/flow/action/SecondApproveAction.java
index 64e8da7..3b80972 100644
--- a/src/main/java/com/biutag/supervision/flow/action/SecondApproveAction.java
+++ b/src/main/java/com/biutag/supervision/flow/action/SecondApproveAction.java
@@ -53,15 +53,19 @@ public class SecondApproveAction implements Action {
     public void updateNegative(String negativeId, String nextFlowKey) {
         Negative negative = negativeService.getById(negativeId);
         LocalDateTime now = LocalDateTime.now();
-        Long secondApprovalTime = negative.getSecondApprovalTime() == null ? 0L : negative.getSecondApprovalTime();
-        if (negative.getLatestProcessTime() != null) {
-            secondApprovalTime = secondApprovalTime + TimeUtil.calculateWorkdayDuration(negative.getLatestProcessTime(), now);
+        Long secondApprovalTime = negative.getSecondApprovalTime();
+        // 覆盖制：每次重新计算，超时锁定则不更新
+        if (TimeUtil.canUpdateApproveTime(secondApprovalTime) && negative.getLatestProcessTime() != null) {
+            secondApprovalTime = TimeUtil.calculateWorkdayDuration(negative.getLatestProcessTime(), now);
         }
         LambdaUpdateWrapper<Negative> updateWrapper = new LambdaUpdateWrapper<Negative>()
                 .set(Negative::getFlowKey, nextFlowKey)
                 .set(Negative::getUpdTime, LocalDateTime.now())
-                .set(Negative::getSecondApprovalTime, secondApprovalTime)
                 .eq(Negative::getId, negativeId);
+        // 超时锁定时，不更新审批时长字段
+        if (TimeUtil.canUpdateApproveTime(secondApprovalTime)) {
+            updateWrapper.set(Negative::getSecondApprovalTime, secondApprovalTime);
+        }
 //        Negative negative = negativeService.getById(negativeId);
         if (ApprovalFlowEnum.SECOND_APPROVAL.getValue().equals(negative.getApprovalFlow())) {
             updateWrapper.set(Negative::getFlowKey, FlowNodeEnum.COMPLETED.getKey())
diff --git a/src/main/java/com/biutag/supervision/flow/action/SecondApproveReturnAction.java b/src/main/java/com/biutag/supervision/flow/action/SecondApproveReturnAction.java
index 5ac468d..68f2d15 100644
--- a/src/main/java/com/biutag/supervision/flow/action/SecondApproveReturnAction.java
+++ b/src/main/java/com/biutag/supervision/flow/action/SecondApproveReturnAction.java
@@ -47,9 +47,10 @@ public class SecondApproveReturnAction implements Action {
     public void updateNegative(String negativeId, String nextFlowKey) {
         Negative negative = negativeService.getById(negativeId);
         LocalDateTime now = LocalDateTime.now();
-        Long secondApprovalTime = negative.getSecondApprovalTime() == null ? 0L : negative.getSecondApprovalTime();
-        if (negative.getLatestProcessTime() != null) {
-            secondApprovalTime = secondApprovalTime + TimeUtil.calculateWorkdayDuration(negative.getLatestProcessTime(), now);
+        Long secondApprovalTime = negative.getSecondApprovalTime();
+        // 覆盖制：每次重新计算，超时锁定则不更新
+        if (TimeUtil.canUpdateApproveTime(secondApprovalTime) && negative.getLatestProcessTime() != null) {
+            secondApprovalTime = TimeUtil.calculateWorkdayDuration(negative.getLatestProcessTime(), now);
         }
         negativeService.update(new LambdaUpdateWrapper<Negative>()
                 .set(Negative::getFlowKey, nextFlowKey)
@@ -57,7 +58,7 @@ public class SecondApproveReturnAction implements Action {
                 .set(Negative::getProcessingStatus, ProcessingStatusEnum.processing.name())
                 // 当前处理对象
                 .set(Negative::getCurrentProcessingObject, String.format("%s专班", negative.getHandleThreeDepartName()))
-                .set(Negative::getSecondApprovalTime, secondApprovalTime)
+                .set(TimeUtil.canUpdateApproveTime(secondApprovalTime), Negative::getSecondApprovalTime, secondApprovalTime)
                 .eq(Negative::getId, negativeId));
     }
 
diff --git a/src/main/java/com/biutag/supervision/util/TimeUtil.java b/src/main/java/com/biutag/supervision/util/TimeUtil.java
index 77145eb..fe91c2c 100644
--- a/src/main/java/com/biutag/supervision/util/TimeUtil.java
+++ b/src/main/java/com/biutag/supervision/util/TimeUtil.java
@@ -18,6 +18,18 @@ public class TimeUtil {
     // 一天86400秒
     public static final Long SECONDS_OF_A_DAY = 86400L;
 
+    // 超时锁定阈值（秒），超过此值则不再更新审批时长
+    public static final Long APPROVAL_LOCK_THRESHOLD = SECONDS_OF_A_DAY;
+
+    /**
+     * 判断审批时长是否可以更新
+     * @param currentDuration 当前审批时长（秒），null表示尚未开始计时
+     * @return true=可以更新，false=已锁定不可更新（>=86400秒）
+     */
+    public static boolean canUpdateApproveTime(Long currentDuration) {
+        return currentDuration == null || currentDuration < APPROVAL_LOCK_THRESHOLD;
+    }
+
     /**
      *
      * @param beginTime
@@ -176,9 +188,9 @@ public class TimeUtil {
         long limit = SECONDS_OF_A_DAY; // 86400秒 = 1天
         long diff = limit - usedSeconds; // diff > 0 表示剩余时间，diff < 0 表示超出时间
         if (diff >= 0) {
-            return "未超时/用时:" + formatDuration(usedSeconds);
+            return "未超时";
         } else {
-            return "已超时/用时:" + formatDuration(usedSeconds);
+            return "已超时";
         }
     }