diff --git a/README.en.md b/README.en.md
index 69de5ad46e07311af885db48addd139ba03b1720..05638f911f116b4d6140bf08aa52984a641aca20 100644
--- a/README.en.md
+++ b/README.en.md
@@ -70,10 +70,10 @@ effect is as follows.
 
 ## Constraints
 
-1. This sample is only supported on Huawei phones running standard systems.
-2. The HarmonyOS version must be HarmonyOS 6.0.0 Release or later.
+1. The sample is only supported on Huawei phones with standard systems.
+2. The HarmonyOS version must be HarmonyOS 5.1.1 Release or later.
 3. The DevEco Studio version must be DevEco Studio 6.0.0 Release or later.
 4. The HarmonyOS SDK version must be HarmonyOS 6.0.0 Release SDK or later.
-5. Both devices must be logged in with the same HUAWEI ID. You are advised to enable Find Device.
-6. Wi-Fi and Bluetooth must be enabled on both devices. If possible, both devices should be connected to the same LAN.
-7. Both devices must have the application installed.
+5. Double-ended devices need to log in to the same Huawei account, so it is recommended to turn on the device finding function.
+6. Double-ended devices need to turn on the Wi-Fi and Bluetooth switches. When conditions permit, it is recommended to connect to the same LAN.
+7. Both end devices need this application.
diff --git a/README.md b/README.md
index 3415b9993cae0a388c2824ae100ffce948aea6a0..1f906e74acd67c8c14452fff714ba5a62bdecbbc 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,7 @@
 ## 约束与限制
 
 1. 本示例仅支持标准系统上运行，支持设备：华为手机。
-2. HarmonyOS系统：HarmonyOS 6.0.0 Release及以上。
+2. HarmonyOS系统：HarmonyOS 5.1.1 Release及以上。
 3. DevEco Studio版本：DevEco Studio 6.0.0 Release及以上。
 4. HarmonyOS SDK版本：HarmonyOS 6.0.0 Release SDK及以上。
 5. 双端设备需要登录同一华为账号，建议打开查找设备功能。
diff --git a/build-profile.json5 b/build-profile.json5
index 164a59ddadecdbc38e4a6bdcb8b331f5820a1193..78d87acf7f94b6ddc566d12b63faaeea3d1d4ea4 100644
--- a/build-profile.json5
+++ b/build-profile.json5
@@ -6,7 +6,7 @@
         "name": "default",
         "signingConfig": "default",
         "targetSdkVersion": "6.0.0(20)",
-        "compatibleSdkVersion": "6.0.0(20)",
+        "compatibleSdkVersion": "5.1.1(19)",
         "runtimeOS": "HarmonyOS"
       }
     ]