diff --git a/YLErpDAL/Modules/TradeModule/DocGenerateModule/GuolianContractNoGenerator.cs b/YLErpDAL/Modules/TradeModule/DocGenerateModule/GuolianContractNoGenerator.cs
index 7c5b9dad..abfa0d4a 100644
--- a/YLErpDAL/Modules/TradeModule/DocGenerateModule/GuolianContractNoGenerator.cs
+++ b/YLErpDAL/Modules/TradeModule/DocGenerateModule/GuolianContractNoGenerator.cs
@@ -38,6 +38,7 @@ namespace YLErp.Modules.TradeModule.DocGenerateModule
 
             lock (_syncLock)
             {
+                // 幂等：如果已生成过确认书编号，直接返回
                 var existingForTrade = dbContext.trade_contract_r
                     .Where(r => r.TradeId == trade.id && r.Type == ContractTypeEnum.Trade && r.IsValid)
                     .Select(r => r.ContractCode)
@@ -48,114 +49,26 @@ namespace YLErp.Modules.TradeModule.DocGenerateModule
                     return existingForTrade;
                 }
 
-                var existingCodes = dbContext.trade_contract_r
-                    .Where(d => d.ContractCode.StartsWith(prefix) && d.Type == ContractTypeEnum.Trade && d.IsValid)
-                    .Select(d => d.ContractCode)
-                    .ToList();
-
-                var existingCodeSet = new HashSet<string>();
-                for (var i = 0; i < existingCodes.Count; i++)
-                {
-                    var code = existingCodes[i];
-                    if (!string.IsNullOrWhiteSpace(code))
-                    {
-                        existingCodeSet.Add(code);
-                    }
-                }
+                // 通过当天同类交易的 id 排序确定序号（幂等）
+                var tradeDateStart = tradeDate.Date;
+                var sameDayTradesCount = dbContext.trade
+                    .Count(t => t.TradeDate >= tradeDateStart
+                        && t.TradeDate < tradeDateStart.AddDays(1)
+                        && t.OpponentRole == trade.OpponentRole
+                        && t.id < trade.id);
+                var sequenceNo = sameDayTradesCount + 1;
 
                 if (isClientTrade)
                 {
-                    // 对客交易：GLMS-{clientCode}-{date}-{counter:D2}-{underlyingCode}
-                    var maxNo = 0;
-                    var prefixLen = prefix.Length;
-                    for (var i = 0; i < existingCodes.Count; i++)
-                    {
-                        var code = existingCodes[i];
-                        if (string.IsNullOrEmpty(code) || code.Length <= prefixLen + 2)
-                        {
-                            continue;
-                        }
-
-                        var counterStr = code.Substring(prefixLen, 2);
-                        if (int.TryParse(counterStr, out var n) && n > maxNo)
-                        {
-                            maxNo = n;
-                        }
-                    }
-
-                    var nextNo = maxNo + 1;
-                    var contractNo = $"{prefix}{nextNo:D2}-{underlyingCode}";
-                    while (existingCodeSet.Contains(contractNo))
-                    {
-                        nextNo++;
-                        contractNo = $"{prefix}{nextNo:D2}-{underlyingCode}";
-                    }
-                    return contractNo;
+                    return $"{prefix}{sequenceNo:D2}-{underlyingCode}";
                 }
                 else
                 {
-                    // 非对客交易：GLMS-{clientCode}-{date}-{letter}-{underlyingCode}
-                    // 找当日已有的非对客交易最大字母序号
-                    var maxLetter = 0;
-                    var prefixLen = prefix.Length;
-                    for (var i = 0; i < existingCodes.Count; i++)
-                    {
-                        var code = existingCodes[i];
-                        if (string.IsNullOrEmpty(code) || code.Length <= prefixLen + 2)
-                        {
-                            continue;
-                        }
-
-                        var rest = code.Substring(prefixLen);
-                        var dashIdx = rest.IndexOf('-');
-                        if (dashIdx > 0)
-                        {
-                            var letterPart = rest.Substring(0, dashIdx);
-                            if (TryParseLettersToNumber(letterPart, out var ln) && ln > maxLetter)
-                            {
-                                maxLetter = ln;
-                            }
-                        }
-                    }
-
-                    var nextLetter = maxLetter + 1;
-                    var contractNo = $"{prefix}{NumberToLetter(nextLetter)}-{underlyingCode}";
-                    while (existingCodeSet.Contains(contractNo))
-                    {
-                        nextLetter++;
-                        contractNo = $"{prefix}{NumberToLetter(nextLetter)}-{underlyingCode}";
-                    }
-                    return contractNo;
+                    return $"{prefix}{NumberToLetter(sequenceNo)}-{underlyingCode}";
                 }
             }
         }
 
-        private static bool TryParseLettersToNumber(string letters, out int number)
-        {
-            number = 0;
-            if (string.IsNullOrEmpty(letters))
-            {
-                return false;
-            }
-
-            for (var i = 0; i < letters.Length; i++)
-            {
-                var c = letters[i];
-                if (c >= 'a' && c <= 'z')
-                {
-                    c = (char)(c - 32);
-                }
-                else if (c < 'A' || c > 'Z')
-                {
-                    number = 0;
-                    return false;
-                }
-
-                number = (number * 26) + (c - 'A' + 1);
-            }
-            return true;
-        }
-
         /// <summary>
         /// 将数字转换为字母序列（1=A, 2=B, 26=Z, 27=AA, 28=AB...）
         /// </summary>