diff --git a/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/controller/ErpFinInvoiceInfoController.java b/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/controller/ErpFinInvoiceInfoController.java
index f07a43db..8777d8d0 100644
--- a/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/controller/ErpFinInvoiceInfoController.java
+++ b/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/controller/ErpFinInvoiceInfoController.java
@@ -142,6 +142,17 @@ public class ErpFinInvoiceInfoController extends BaseController {
         return R.ok(list);
     }
 
+    /**
+     * 按合同查询累计回款比例最大的开票单累计回款金额
+     */
+    @SaCheckPermission("oa/erp:finInvoiceInfo:query")
+    @GetMapping("/getMaxReturnedMoneyByContractId/{contractId}")
+    public R<java.math.BigDecimal> getMaxReturnedMoneyByContractId(@NotNull(message = "contractId不能为空")
+                                                                   @PathVariable("contractId") Long contractId,
+                                                                   @RequestParam(required = false) Long excludeInvoiceId) {
+        return R.ok(erpFinInvoiceInfoService.getMaxReturnedMoneyByContractId(contractId, excludeInvoiceId));
+    }
+
 
     /**
      * 修改开票发票附件信息
diff --git a/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/service/IErpFinInvoiceInfoService.java b/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/service/IErpFinInvoiceInfoService.java
index d7c31465..b4b0387e 100644
--- a/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/service/IErpFinInvoiceInfoService.java
+++ b/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/service/IErpFinInvoiceInfoService.java
@@ -8,6 +8,7 @@ import org.dromara.common.mybatis.core.page.TableDataInfo;
 import org.dromara.common.mybatis.core.page.PageQuery;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.math.BigDecimal;
 import java.util.Collection;
 import java.util.List;
 
@@ -83,4 +84,13 @@ public interface IErpFinInvoiceInfoService {
      * @return 是否修改成功
      */
     public Boolean updateInvoiceAttachByBo(ErpFinInvoiceInfoBo bo);
+
+    /**
+     * 按合同查询累计回款比例最大的开票单累计回款金额
+     *
+     * @param contractId       合同ID
+     * @param excludeInvoiceId 排除的开票ID（编辑当前单时使用）
+     * @return 累计回款金额，无记录时返回0
+     */
+    BigDecimal getMaxReturnedMoneyByContractId(Long contractId, Long excludeInvoiceId);
 }
diff --git a/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/service/impl/ErpFinInvoiceInfoServiceImpl.java b/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/service/impl/ErpFinInvoiceInfoServiceImpl.java
index 0f94b8fc..30a0bf3c 100644
--- a/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/service/impl/ErpFinInvoiceInfoServiceImpl.java
+++ b/ruoyi-modules/ruoyi-oa/src/main/java/org/dromara/oa/erp/service/impl/ErpFinInvoiceInfoServiceImpl.java
@@ -378,6 +378,32 @@ public class ErpFinInvoiceInfoServiceImpl extends AbstractWorkflowService<ErpFin
         return erpContractPaymentMethodVoList;
     }
 
+    /**
+     * 按合同查询累计回款比例最大的开票单累计回款金额
+     */
+    @Override
+    public BigDecimal getMaxReturnedMoneyByContractId(Long contractId, Long excludeInvoiceId) {
+        if (contractId == null) {
+            return ZERO;
+        }
+        LambdaQueryWrapper<ErpFinInvoiceInfo> qw = Wrappers.lambdaQuery(ErpFinInvoiceInfo.class)
+            .eq(ErpFinInvoiceInfo::getContractId, contractId)
+            .eq(ErpFinInvoiceInfo::getDelFlag, DataConstants.DEL_FLAG_NORMAL)
+            .ne(ErpFinInvoiceInfo::getInvoiceStatus, OAStatusEnum.INVALID.getStatus())
+            .isNotNull(ErpFinInvoiceInfo::getReturnedRate)
+            .orderByDesc(ErpFinInvoiceInfo::getReturnedRate)
+            .orderByDesc(ErpFinInvoiceInfo::getInvoiceId)
+            .last("LIMIT 1");
+        if (excludeInvoiceId != null) {
+            qw.ne(ErpFinInvoiceInfo::getInvoiceId, excludeInvoiceId);
+        }
+        ErpFinInvoiceInfo invoiceInfo = baseMapper.selectOne(qw);
+        if (invoiceInfo == null || invoiceInfo.getReturnedMoney() == null) {
+            return ZERO;
+        }
+        return invoiceInfo.getReturnedMoney();
+    }
+
 
     /**
      * 修改发票附件信息