diff --git a/src/Pay/EasyAbp.Abp.WeChat.Pay.Abstractions/RequestHandling/Dtos/GetJsSdkWeChatPayParametersInput.cs b/src/Pay/EasyAbp.Abp.WeChat.Pay.Abstractions/RequestHandling/Dtos/GetJsSdkWeChatPayParametersInput.cs
index e90a751..578c009 100644
--- a/src/Pay/EasyAbp.Abp.WeChat.Pay.Abstractions/RequestHandling/Dtos/GetJsSdkWeChatPayParametersInput.cs
+++ b/src/Pay/EasyAbp.Abp.WeChat.Pay.Abstractions/RequestHandling/Dtos/GetJsSdkWeChatPayParametersInput.cs
@@ -1,11 +1,13 @@
 using System;
 using System.ComponentModel.DataAnnotations;
+using JetBrains.Annotations;
 
 namespace EasyAbp.Abp.WeChat.Pay.RequestHandling.Dtos;
 
 [Serializable]
 public class GetJsSdkWeChatPayParametersInput
 {
+    [CanBeNull]
     public string MchId { get; set; }
 
     [Required]
diff --git a/src/Pay/EasyAbp.Abp.WeChat.Pay/RequestHandling/WeChatPayClientRequestHandlingService.cs b/src/Pay/EasyAbp.Abp.WeChat.Pay/RequestHandling/WeChatPayClientRequestHandlingService.cs
index 22476a1..980f925 100644
--- a/src/Pay/EasyAbp.Abp.WeChat.Pay/RequestHandling/WeChatPayClientRequestHandlingService.cs
+++ b/src/Pay/EasyAbp.Abp.WeChat.Pay/RequestHandling/WeChatPayClientRequestHandlingService.cs
@@ -1,25 +1,23 @@
-using System.Security.Cryptography;
+using System.Text;
 using System.Threading.Tasks;
 using EasyAbp.Abp.WeChat.Common.Extensions;
-using EasyAbp.Abp.WeChat.Common.Infrastructure;
-using EasyAbp.Abp.WeChat.Common.Infrastructure.Signature;
 using EasyAbp.Abp.WeChat.Pay.Options;
 using EasyAbp.Abp.WeChat.Pay.RequestHandling.Dtos;
+using EasyAbp.Abp.WeChat.Pay.Security;
 using Volo.Abp.DependencyInjection;
 
 namespace EasyAbp.Abp.WeChat.Pay.RequestHandling;
 
 public class WeChatPayClientRequestHandlingService : IWeChatPayClientRequestHandlingService, ITransientDependency
 {
+    private readonly ICertificatesManager _certificatesManager;
     private readonly IAbpWeChatPayOptionsProvider _optionsProvider;
-    private readonly ISignatureGenerator _signatureGenerator;
 
-    public WeChatPayClientRequestHandlingService(
-        IAbpWeChatPayOptionsProvider optionsProvider,
-        ISignatureGenerator signatureGenerator)
+    public WeChatPayClientRequestHandlingService(ICertificatesManager certificatesManager,
+        IAbpWeChatPayOptionsProvider optionsProvider)
     {
+        _certificatesManager = certificatesManager;
         _optionsProvider = optionsProvider;
-        _signatureGenerator = signatureGenerator;
     }
 
     public virtual async Task<GetJsSdkWeChatPayParametersResult> GetJsSdkWeChatPayParametersAsync(
@@ -32,20 +30,18 @@ public virtual async Task<GetJsSdkWeChatPayParametersResult> GetJsSdkWeChatPayPa
 
         var options = await _optionsProvider.GetAsync(input.MchId);
 
+        const string signType = "RSA";
         var nonceStr = RandomStringHelper.GetRandomString();
         var timeStamp = DateTimeHelper.GetNowTimeStamp();
         var package = $"prepay_id={input.PrepayId}";
 
-        const string signType = "MD5";
-
-        var @params = new WeChatParameters();
-        @params.AddParameter("appId", input.AppId);
-        @params.AddParameter("nonceStr", nonceStr);
-        @params.AddParameter("timeStamp", timeStamp);
-        @params.AddParameter("package", package);
-        @params.AddParameter("signType", signType);
-
-        var paySign = _signatureGenerator.Generate(@params, MD5.Create(), options.ApiV3Key);
+        var waitSignString = new StringBuilder();
+        waitSignString.Append(input.AppId).Append('\n')
+            .Append(timeStamp).Append('\n')
+            .Append(nonceStr).Append('\n')
+            .Append("prepay_id=").Append(input.PrepayId).Append('\n');
+        var certificate = await _certificatesManager.GetCertificateAsync(options.MchId);
+        var paySign = _certificatesManager.GetSignature(waitSignString.ToString(), certificate);
 
         return new GetJsSdkWeChatPayParametersResult(nonceStr, timeStamp, package, signType, paySign);
     }
diff --git a/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/CertificatesManager.cs b/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/CertificatesManager.cs
index d7bd59f..45495bc 100644
--- a/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/CertificatesManager.cs
+++ b/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/CertificatesManager.cs
@@ -1,5 +1,8 @@
 using System;
 using System.Collections.Concurrent;
+using System.Security.Cryptography;
+using System.Security.Cryptography.X509Certificates;
+using System.Text;
 using System.Threading.Tasks;
 using EasyAbp.Abp.WeChat.Pay.Options;
 using Volo.Abp.BlobStoring;
@@ -36,6 +39,14 @@ public async Task<WeChatPayCertificate> GetCertificateAsync(string mchId)
                 new WeChatPayCertificate(options.MchId, certificateBytes, options.CertificateSecret))).Value;
     }
 
+    public string GetSignature(string pendingSignature, WeChatPayCertificate certificate)
+    {
+        var privateKey = certificate.X509Certificate.GetRSAPrivateKey();
+        var signDataBytes = privateKey.SignData(Encoding.UTF8.GetBytes(pendingSignature), HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
+
+        return Convert.ToBase64String(signDataBytes);
+    }
+
     protected virtual async Task<byte[]> GetX509CertificateBytesAsync(AbpWeChatPayOptions options)
     {
         if (options.CertificateBlobName.IsNullOrEmpty())
diff --git a/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/ICertificatesManager.cs b/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/ICertificatesManager.cs
index 4346b02..ed3e3a2 100644
--- a/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/ICertificatesManager.cs
+++ b/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/ICertificatesManager.cs
@@ -16,4 +16,12 @@ public interface ICertificatesManager
     /// <exception cref="ArgumentNullException">当证书的 BLOB 不存在时抛出此异常。</exception>
     /// <exception cref="NullReferenceException">无法获取证书时会抛出此异常。</exception>
     Task<WeChatPayCertificate> GetCertificateAsync(string mchId);
+
+    /// <summary>
+    /// 使用微信支付证书对待签名字符串进行签名。
+    /// </summary>
+    /// <param name="pendingSignature">等待签名的字符串。</param>
+    /// <param name="certificate">用于签名的证书实例。</param>
+    /// <returns>具体的签名数据，使用 Base64 编码。</returns>
+    string GetSignature(string pendingSignature, WeChatPayCertificate certificate);
 }
\ No newline at end of file
diff --git a/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/WeChatPayAuthorizationGenerator.cs b/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/WeChatPayAuthorizationGenerator.cs
index cde9743..ee75893 100644
--- a/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/WeChatPayAuthorizationGenerator.cs
+++ b/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/WeChatPayAuthorizationGenerator.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Net.Http;
-using System.Security.Cryptography;
-using System.Security.Cryptography.X509Certificates;
-using System.Text;
+using System.Net.Http;
 using System.Threading.Tasks;
 using EasyAbp.Abp.WeChat.Common.Extensions;
 using EasyAbp.Abp.WeChat.Pay.ApiRequests;
@@ -21,7 +17,7 @@ public class WeChatPayAuthorizationGenerator : IWeChatPayAuthorizationGenerator,
     /// 授权(Authorization)标头的认证类型。
     /// </summary>
     public const string AuthorizationScheme = "WECHATPAY2-SHA256-RSA2048";
-    
+
     private readonly IAbpWeChatPayOptionsProvider _weChatPayOptionsProvider;
     private readonly ICertificatesManager _certificatesManager;
 
@@ -41,17 +37,9 @@ public async Task<string> GenerateAuthorizationAsync(HttpMethod method, string u
         var requestModel = new WeChatPayApiRequestModel(method, url, body, timeStamp, nonceStr);
         var pendingSignature = requestModel.GetPendingSignatureString();
         var certificate = await _certificatesManager.GetCertificateAsync(mchId);
-        var signString = RsaSign(pendingSignature, certificate);
+        var signString = _certificatesManager.GetSignature(pendingSignature, certificate);
 
         return
             $"{AuthorizationScheme} mchid=\"{options.MchId}\",nonce_str=\"{nonceStr}\",timestamp=\"{timeStamp}\",serial_no=\"{certificate.X509Certificate.SerialNumber}\",signature=\"{signString}\"";
     }
-
-    private string RsaSign(string pendingSignature, WeChatPayCertificate certificate)
-    {
-        var privateKey = certificate.X509Certificate.GetRSAPrivateKey();
-        var signDataBytes = privateKey.SignData(Encoding.UTF8.GetBytes(pendingSignature), HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
-
-        return Convert.ToBase64String(signDataBytes);
-    }
 }
\ No newline at end of file
diff --git a/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/WeChatPayCertificate.cs b/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/WeChatPayCertificate.cs
index 0430071..56fe601 100644
--- a/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/WeChatPayCertificate.cs
+++ b/src/Pay/EasyAbp.Abp.WeChat.Pay/Security/WeChatPayCertificate.cs
@@ -28,7 +28,7 @@ public sealed class WeChatPayCertificate
     /// </summary>
     /// <param name="mchId">商户号。</param>
     /// <param name="certificateBytes">X509 证书实例。</param>
-    /// <param name="password">X509 证书的哈希值，用于快速比对证书是否发生变化。</param>
+    /// <param name="password">X509 证书的密码。</param>
     public WeChatPayCertificate(string mchId, byte[] certificateBytes, string password)
     {
         MchId = mchId;