diff --git a/src/main/java/dev/flyfish/boot/cas/filter/CASFilter.java b/src/main/java/dev/flyfish/boot/cas/filter/CASFilter.java
index f8c644d..4d30a09 100644
--- a/src/main/java/dev/flyfish/boot/cas/filter/CASFilter.java
+++ b/src/main/java/dev/flyfish/boot/cas/filter/CASFilter.java
@@ -120,7 +120,7 @@ public class CASFilter implements WebFilter {
         if (parameter.casServiceUrl != null) {
             serviceString = URLEncoder.encode(parameter.casServiceUrl, StandardCharsets.UTF_8);
         } else {
-            serviceString = computeService(context, parameter.casServerName);
+            serviceString = computeService(context, parameter.getFullServerUrl());
         }
 
         if (log.isTraceEnabled()) {
@@ -136,12 +136,11 @@ public class CASFilter implements WebFilter {
      * @param server  服务
      * @return 结果
      */
-    public static String computeService(CASContext context, String server) {
+    public String computeService(CASContext context, String server) {
         if (log.isTraceEnabled()) {
             log.trace("entering getService({}, {})", context, server);
         }
 
-
         if (server == null) {
             log.error("getService() argument \"server\" was illegally null.");
             throw new IllegalArgumentException("name of server is required");
@@ -149,13 +148,8 @@ public class CASFilter implements WebFilter {
 
         URI uri = context.getRequest().getURI();
 
-        StringBuilder sb = new StringBuilder();
-        if (server.startsWith("http")) {
-            sb.append(server);
-        } else {
-            sb.append(uri.getScheme()).append("://").append(server);
-        }
-        sb.append(uri.getPath());
+        StringBuilder sb = new StringBuilder(server).append(uri.getPath());
+
         if (uri.getQuery() != null) {
             String query = uri.getQuery();
 
diff --git a/src/main/java/dev/flyfish/boot/cas/filter/CASParameter.java b/src/main/java/dev/flyfish/boot/cas/filter/CASParameter.java
index a9827d6..9278e69 100644
--- a/src/main/java/dev/flyfish/boot/cas/filter/CASParameter.java
+++ b/src/main/java/dev/flyfish/boot/cas/filter/CASParameter.java
@@ -2,6 +2,7 @@ package dev.flyfish.boot.cas.filter;
 
 import com.fasterxml.jackson.annotation.JsonAlias;
 import lombok.Data;
+import org.springframework.util.StringUtils;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -27,6 +28,8 @@ public class CASParameter {
     @JsonAlias(CASFilter.SERVERNAME_INIT_PARAM)
     String casServerName;
 
+    String casServerProtocol = "http";
+
     @JsonAlias(CASFilter.PROXY_CALLBACK_INIT_PARAM)
     String casProxyCallbackUrl;
 
@@ -60,6 +63,13 @@ public class CASParameter {
         }
     }
 
+    public String getFullServerUrl() {
+        if (StringUtils.hasText(casServerName)) {
+            return casServerProtocol + "://" + casServerName;
+        }
+        return null;
+    }
+
     /**
      * 检查配置参数是否有误
      */
diff --git a/src/main/resources/application.yml b/src/main/resources/application.yml
index 189d57d..3f2602b 100644
--- a/src/main/resources/application.yml
+++ b/src/main/resources/application.yml
@@ -9,6 +9,8 @@ cas:
   filter:
     cas-login: https://sdsfzt.sxu.edu.cn/authserver/login
     cas-validate: https://sdsfzt.sxu.edu.cn/authserver/serviceValidate
-    cas-server-name: https://magnetic-first-yak.ngrok-free.app
+    cas-server-protocol: https
+    cas-server-name: magnetic-first-yak.ngrok-free.app
     cas-init-context-class: dev.flyfish.boot.cas.filter.CASLoginFilter
+
 debug: true