diff --git a/ruoyi-modules/hwmom-dms/src/main/java/org/dromara/dms/service/impl/DmsBillsMaintDetailServiceImpl.java b/ruoyi-modules/hwmom-dms/src/main/java/org/dromara/dms/service/impl/DmsBillsMaintDetailServiceImpl.java
index 46190cde..8773043c 100644
--- a/ruoyi-modules/hwmom-dms/src/main/java/org/dromara/dms/service/impl/DmsBillsMaintDetailServiceImpl.java
+++ b/ruoyi-modules/hwmom-dms/src/main/java/org/dromara/dms/service/impl/DmsBillsMaintDetailServiceImpl.java
@@ -19,6 +19,7 @@ import org.dromara.dms.service.IDmsBillsMaintDetailService;
 import org.springframework.stereotype.Service;
 
 import java.util.*;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
 /**
@@ -179,6 +180,7 @@ public class DmsBillsMaintDetailServiceImpl implements IDmsBillsMaintDetailServi
         List<DmsBillsMaintDetail> details = baseMapper.selectList(
             Wrappers.<DmsBillsMaintDetail>lambdaQuery()
                 .eq(DmsBillsMaintDetail::getMachineId, machineId)
+                .isNotNull(DmsBillsMaintDetail::getMaintInstanceId)
         );
 
         if (details.isEmpty()) {
@@ -188,6 +190,7 @@ public class DmsBillsMaintDetailServiceImpl implements IDmsBillsMaintDetailServi
         // 提取唯一的工单ID
         Set<Long> maintInstanceIds = details.stream()
             .map(DmsBillsMaintDetail::getMaintInstanceId)
+            .filter(Objects::nonNull)
             .collect(Collectors.toSet());
 
         // 查询工单主表信息
@@ -214,11 +217,13 @@ public class DmsBillsMaintDetailServiceImpl implements IDmsBillsMaintDetailServi
             Wrappers.<DmsBillsMaintDetail>lambdaQuery()
                 .select(DmsBillsMaintDetail::getMaintInstanceId)
                 .eq(DmsBillsMaintDetail::getMachineId, machineId)
+                .isNotNull(DmsBillsMaintDetail::getMaintInstanceId)
         );
 
         // 统计唯一的工单数量
         return (long) details.stream()
             .map(DmsBillsMaintDetail::getMaintInstanceId)
+            .filter(Objects::nonNull)
             .collect(Collectors.toSet())
             .size();
     }