diff --git a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Program.cs b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Program.cs
index e8b14218..973633ba 100644
--- a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Program.cs
+++ b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Program.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Hosting;
 
diff --git a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/BackgroundServices/TenpayCertificateRefreshingBackgroundService.cs b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/BackgroundServices/TenpayCertificateRefreshingBackgroundService.cs
index 80529d8b..3077caaf 100644
--- a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/BackgroundServices/TenpayCertificateRefreshingBackgroundService.cs
+++ b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/BackgroundServices/TenpayCertificateRefreshingBackgroundService.cs
@@ -14,18 +14,15 @@ namespace SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5.Services.BackgroundSe
     {
         private readonly ILogger _logger;
         private readonly Options.TenpayOptions _tenpayOptions;
-        private readonly CertificateManager _tenpayCertificateManager;
         private readonly HttpClients.IWechatTenpayHttpClientFactory _tenpayHttpClientFactory;
 
         public TenpayCertificateRefreshingBackgroundService(
             ILoggerFactory loggerFactory,
             IOptions<Options.TenpayOptions> tenpayOptions,
-            CertificateManager tenpayCertificateManager,
             HttpClients.IWechatTenpayHttpClientFactory tenpayHttpClientFactory)
         {
             _logger = loggerFactory.CreateLogger(GetType());
             _tenpayOptions = tenpayOptions.Value;
-            _tenpayCertificateManager = tenpayCertificateManager;
             _tenpayHttpClientFactory = tenpayHttpClientFactory;
         }
 
@@ -52,7 +49,7 @@ namespace SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5.Services.BackgroundSe
 
                         foreach (var certificateModel in response.CertificateList)
                         {
-                            _tenpayCertificateManager.AddEntry(new CertificateEntry(certificateModel));
+                            client.CertificateManager.AddEntry(new CertificateEntry(certificateModel));
                         }
 
                         _logger.LogInformation("刷新微信商户平台证书成功。");
diff --git a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/IWechatTenpayCertificateManagerFactory.cs b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/IWechatTenpayCertificateManagerFactory.cs
new file mode 100644
index 00000000..8268e793
--- /dev/null
+++ b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/IWechatTenpayCertificateManagerFactory.cs
@@ -0,0 +1,9 @@
+namespace SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5.Services.HttpClients
+{
+    using SKIT.FlurlHttpClient.Wechat.TenpayV3.Settings;
+
+    public interface IWechatTenpayCertificateManagerFactory
+    {
+        CertificateManager Create(string merchantId);
+    }
+}
diff --git a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/IWechatTenpayHttpClientFactory.cs b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/IWechatTenpayHttpClientFactory.cs
index 0b1fc5a8..fa5e8ad5 100644
--- a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/IWechatTenpayHttpClientFactory.cs
+++ b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/IWechatTenpayHttpClientFactory.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
-
-namespace SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5.Services.HttpClients
+namespace SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5.Services.HttpClients
 {
     public interface IWechatTenpayHttpClientFactory
     {
diff --git a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/Implements/WechatTenpayCertificateManagerFactory.cs b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/Implements/WechatTenpayCertificateManagerFactory.cs
new file mode 100644
index 00000000..19143ede
--- /dev/null
+++ b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/Implements/WechatTenpayCertificateManagerFactory.cs
@@ -0,0 +1,21 @@
+using System.Collections.Concurrent;
+
+namespace SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5.Services.HttpClients.Implements
+{
+    using SKIT.FlurlHttpClient.Wechat.TenpayV3.Settings;
+
+    partial class WechatTenpayCertificateManagerFactory : IWechatTenpayCertificateManagerFactory
+    {
+        private readonly ConcurrentDictionary<string, CertificateManager> _dict;
+
+        public WechatTenpayCertificateManagerFactory()
+        {
+            _dict = new ConcurrentDictionary<string, CertificateManager>();
+        }
+
+        public CertificateManager Create(string merchantId)
+        {
+            return _dict.GetOrAdd(merchantId, new InMemoryCertificateManager());
+        }
+    }
+}
diff --git a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/Implements/WechatTenpayHttpClientFactory.cs b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/Implements/WechatTenpayHttpClientFactory.cs
index b7b366bc..12846b89 100644
--- a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/Implements/WechatTenpayHttpClientFactory.cs
+++ b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Services/HttpClients/Implements/WechatTenpayHttpClientFactory.cs
@@ -12,34 +12,34 @@ namespace SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5.Services.HttpClients.
     partial class WechatTenpayHttpClientFactory : IWechatTenpayHttpClientFactory
     {
         private readonly System.Net.Http.IHttpClientFactory _httpClientFactory;
-        private readonly Options.TenpayOptions _wechatOptions;
-        private readonly CertificateManager _certificateManager;
+        private readonly Options.TenpayOptions _tenpayOptions;
+        private readonly IWechatTenpayCertificateManagerFactory _tenpayCertificateManagerFactory;
 
         public WechatTenpayHttpClientFactory(
             System.Net.Http.IHttpClientFactory httpClientFactory,
-            IOptions<Options.TenpayOptions> wechatOptions,
-            CertificateManager certificateManager)
+            IOptions<Options.TenpayOptions> tenpayOptions,
+            IWechatTenpayCertificateManagerFactory tenpayCertificateManagerFactory)
         {
             _httpClientFactory = httpClientFactory;
-            _wechatOptions = wechatOptions.Value;
-            _certificateManager = certificateManager;
+            _tenpayOptions = tenpayOptions.Value;
+            _tenpayCertificateManagerFactory = tenpayCertificateManagerFactory;
 
             FlurlHttp.GlobalSettings.FlurlClientFactory = new DelegatingFlurlClientFactory(_httpClientFactory);
         }
 
         public WechatTenpayClient Create(string merchantId)
         {
-            var wechatMerchant = _wechatOptions.Merchants?.FirstOrDefault(e => string.Equals(merchantId, e.MerchantId));
-            if (wechatMerchant == null)
+            var merchantOptions = _tenpayOptions.Merchants?.FirstOrDefault(e => string.Equals(merchantId, e.MerchantId));
+            if (merchantOptions == null)
                 throw new Exception("未在配置项中找到该 MerchantId 对应的微信商户号。");
 
             return new WechatTenpayClient(new WechatTenpayClientOptions()
             {
-                MerchantId = wechatMerchant.MerchantId,
-                MerchantV3Secret = wechatMerchant.SecretV3,
-                MerchantCertSerialNumber = wechatMerchant.CertSerialNumber,
-                MerchantCertPrivateKey = wechatMerchant.CertPrivateKey,
-                CertificateManager = _certificateManager,
+                MerchantId = merchantOptions.MerchantId,
+                MerchantV3Secret = merchantOptions.SecretV3,
+                MerchantCertSerialNumber = merchantOptions.CertSerialNumber,
+                MerchantCertPrivateKey = merchantOptions.CertPrivateKey,
+                CertificateManager = _tenpayCertificateManagerFactory.Create(merchantOptions.MerchantId),
                 AutoEncryptRequestSensitiveProperty = true,
                 AutoDecryptResponseSensitiveProperty = true
             });
diff --git a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Startup.cs b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Startup.cs
index 789e278f..a220645e 100644
--- a/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Startup.cs
+++ b/samples/SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5/Startup.cs
@@ -1,17 +1,10 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
-using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5
 {
-    using SKIT.FlurlHttpClient.Wechat.TenpayV3.Settings;
-
     public class Startup
     {
         public IConfiguration Configuration { get; }
@@ -31,7 +24,7 @@ namespace SKIT.FlurlHttpClient.Wechat.TenpayV3.Sample_Net5
 
             // ע�빤�� HTTP �ͻ���
             services.AddHttpClient();
-            services.AddSingleton<CertificateManager, InMemoryCertificateManager>();
+            services.AddSingleton<Services.HttpClients.IWechatTenpayCertificateManagerFactory, Services.HttpClients.Implements.WechatTenpayCertificateManagerFactory>();
             services.AddSingleton<Services.HttpClients.IWechatTenpayHttpClientFactory, Services.HttpClients.Implements.WechatTenpayHttpClientFactory>();
 
             // ע���̨����