diff --git a/YLErpDAL/Modules/TradeModule/OAModels.cs b/YLErpDAL/Modules/TradeModule/OAModels.cs
index 35dab7a2..ca9c68d9 100644
--- a/YLErpDAL/Modules/TradeModule/OAModels.cs
+++ b/YLErpDAL/Modules/TradeModule/OAModels.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 
 namespace YLErp.Modules.TradeModule
 {
@@ -41,4 +42,23 @@ namespace YLErp.Modules.TradeModule
         public string msg { get; set; }
         public string requestid { get; set; }
     }
+
+    /// <summary>
+    /// 附件上传接口响应模型
+    /// </summary>
+    public class UploadAttachmentResponse
+    {
+        public int code { get; set; }
+        public List<UploadAttachmentData> data { get; set; }
+        public string status { get; set; }
+    }
+
+    /// <summary>
+    /// 附件上传接口响应数据模型
+    /// </summary>
+    public class UploadAttachmentData
+    {
+        public string annexId { get; set; }
+        public string annexName { get; set; }
+    }
 }
\ No newline at end of file
diff --git a/YLErpDAL/Modules/TradeModule/TradeOAService.cs b/YLErpDAL/Modules/TradeModule/TradeOAService.cs
index 669fb837..90f6df0a 100644
--- a/YLErpDAL/Modules/TradeModule/TradeOAService.cs
+++ b/YLErpDAL/Modules/TradeModule/TradeOAService.cs
@@ -97,6 +97,78 @@ namespace YLErp.Modules.TradeModule
             }
         }
 
+        /// <summary>
+        /// 上传附件到OA系统
+        /// </summary>
+        /// <param name="filePath">文件路径</param>
+        /// <returns>附件ID列表</returns>
+        private async Task<List<string>> UploadAttachmentAsync(string filePath)
+        {
+            try
+            {
+                // 从配置文件读取上传配置
+                var oaConfigSection = AppManager.GetConfiguration().GetSection("oa_confg");
+                var uploadUrl = oaConfigSection["UploadUrl"];
+                var systemToken = oaConfigSection["SystemToken"];
+
+                if (string.IsNullOrEmpty(uploadUrl))
+                {
+                    logger.Error("OA接口配置中UploadUrl为空");
+                    throw new Exception("OA接口配置中上传地址为空");
+                }
+                if (string.IsNullOrEmpty(systemToken))
+                {
+                    logger.Error("OA接口配置中SystemToken为空");
+                    throw new Exception("OA接口配置中上传令牌为空");
+                }
+
+                if (!File.Exists(filePath))
+                {
+                    logger.Error($"附件文件不存在：{filePath}");
+                    throw new Exception("附件文件不存在");
+                }
+
+                // 创建multipart/form-data请求
+                using (var httpClient = new HttpClient())
+                using (var form = new MultipartFormDataContent())
+                {
+                    // 添加文件
+                    var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
+                    var fileName = Path.GetFileName(filePath);
+                    form.Add(new StreamContent(fileStream), "file", fileName);
+
+                    // 添加systemToken
+                    form.Add(new StringContent(systemToken), "systemToken");
+
+                    // 发送请求
+                    var response = await httpClient.PostAsync(uploadUrl, form);
+                    var responseContent = await response.Content.ReadAsStringAsync();
+
+                    logger.Info($"附件上传接口返回: {responseContent}");
+
+                    // 解析响应
+                    var uploadResponse = JsonHelper.Deserialize<UploadAttachmentResponse>(responseContent);
+                    if (uploadResponse.code == 0 && uploadResponse.data != null)
+                    {
+                        // 提取annexId
+                        var annexIds = uploadResponse.data.Select(item => item.annexId).ToList();
+                        logger.Info($"成功上传附件，获取到{annexIds.Count}个附件ID");
+                        return annexIds;
+                    }
+                    else
+                    {
+                        logger.Error($"附件上传失败：{uploadResponse.status}");
+                        throw new Exception($"附件上传失败：{uploadResponse.status}");
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                logger.Error($"上传附件时发生异常：{ex.Message}", ex);
+                throw;
+            }
+        }
+
         /// <summary>
         /// 调用OA接口
         /// </summary>
@@ -130,29 +202,18 @@ namespace YLErp.Modules.TradeModule
                 }
 
                 // 处理附件
-                string attachmentBase64 = null;
-                string attachmentFileName = null;
+                List<string> annexIds = null;
                 if (tdoc != null && !string.IsNullOrEmpty(tdoc.AbsolutePath))
                 {
                     try
                     {
-                        if (File.Exists(tdoc.AbsolutePath))
-                        {
-                            var fileBytes = await File.ReadAllBytesAsync(tdoc.AbsolutePath);
-                            attachmentBase64 = Convert.ToBase64String(fileBytes);
-                            attachmentFileName = Path.GetFileName(tdoc.AbsolutePath);
-                            logger.Info($"成功读取附件文件：{tdoc.AbsolutePath}，文件大小：{fileBytes.Length} 字节");
-                        }
-                        else
-                        {
-                            logger.Error($"附件文件不存在：{tdoc.AbsolutePath}");
-                            return new GuoLianOAResponse() { code = -1, data = new GuoLianOAData { msg = "附件文件不存在" } };
-                        }
+                        annexIds = await UploadAttachmentAsync(tdoc.AbsolutePath);
+                        logger.Info($"成功上传附件并获取到annexId：{string.Join(", ", annexIds)}");
                     }
                     catch (Exception ex)
                     {
-                        logger.Error($"读取附件文件失败：{tdoc.AbsolutePath}，错误：{ex.Message}", ex);
-                        return new GuoLianOAResponse() { code = -1, data = new GuoLianOAData { msg = "读取附件文件失败" } };
+                        logger.Error($"上传附件失败：{tdoc.AbsolutePath}，错误：{ex.Message}", ex);
+                        return new GuoLianOAResponse() { code = -1, data = new GuoLianOAData { msg = "上传附件失败" } };
                     }
                 }
 
@@ -184,7 +245,8 @@ namespace YLErp.Modules.TradeModule
                     contractSignDate = DateTime.Now.ToString("yyyyMMdd"),
                     signIntegrityAgreement = "无需签订",
                     contractBackground = $"我司与{trade.ClientName}已完成NAFMII协议签署，并开展TRS交易：{contractCode}，参与标的{trade.UnderlyingCode} {trade.UnderlyingName}，参与标的数量面额{trade.OriginalStockEqvNotional}元人民币",
-                    //需要上传接口加附件
+                    // 使用annexId替代Base64编码
+                    annexIds = annexIds
                 };
 
                 // 构建查询参数（不包含dataMap，dataMap放在请求体中）
diff --git a/YLErpWeb/appsettings.dev.json b/YLErpWeb/appsettings.dev.json
index 25774d4a..99e05c75 100644
--- a/YLErpWeb/appsettings.dev.json
+++ b/YLErpWeb/appsettings.dev.json
@@ -77,10 +77,11 @@
   "oa_confg": {
     "BaseUrl": "http://10.52.130.11",
     "SubUrl": "/ZSZQ/fileDraft",
-    "SystemToken": "fF2U9HXs7dm6Hjz5X", //OA系统key
+    "SystemToken": "123", //OA系统key
     "SystemName": "ZSZQ_CWYSPJYQRSDZWF", //OA文件类别
     "IsNextFlow": 0, //是否自动提交 默认0
-    "FlowId": 723606
+    "FlowId": 723606,
+    "UploadUrl": "http://172.28.40.132:13590/gateway/oaflow/uploadDoc"
   },
   "GeneralSSO": {
     "enable": true, //是否启用通用SSO登录