diff --git a/choose-cn.sh b/choose-cn.sh
new file mode 100644
index 0000000..565d7e2
--- /dev/null
+++ b/choose-cn.sh
@@ -0,0 +1,60 @@
+#!/bin/bash
+
+# 使用 dig 命令查询 DNS 记录并写入 ip.txt
+dig cf.youoffer.net A +short > ip.txt
+
+# 创建一个新的文件 ip_use.txt
+touch ip_use.txt
+
+# 读取 ip.txt 中的每个 IP 地址
+while IFS= read -r ip
+do
+    # 使用 ping 命令检查延迟
+    ping_result=$(ping -c 1 -W 1 "$ip" | grep ttl)
+  
+    # 如果 ping 成功
+    if [ $? -eq 0 ]; then
+        # 提取延迟时间
+        ping_time=$(echo "$ping_result" | cut -d'=' -f 4 | cut -d' ' -f 1)
+    
+        # 如果延迟时间小于 150ms
+        if (( $(echo "$ping_time < 150" | bc -l) )); then
+            echo "Ping to $ip successful with a latency of $ping_time ms"
+            # 将小于 150ms 的 IP 写入 ip_use.txt
+            echo "$ip" >> ip_use.txt
+        else
+            echo "Ping to $ip discarded due to high latency of $ping_time ms"
+        fi
+    else
+        echo "Ping to $ip failed"
+    fi
+done < ip.txt
+
+# 读取 ip_use.txt 中的每个 IP 地址进行下载测试
+while IFS= read -r ip
+do
+    echo "Starting download test for $ip"
+    # 使用 curl 命令进行下载测试
+    start_time=$(date +%s.%N)
+    curl -s --resolve speed.cloudflare.com:443:"$ip" https://speed.cloudflare.com/__down?bytes=10000000 -o /dev/null --connect-timeout 5
+    curl_status=$?
+    end_time=$(date +%s.%N)
+    elapsed_time=$(echo "$end_time - $start_time" | bc)
+    
+    # 检查 curl 命令的返回状态
+    if [ $curl_status -eq 0 ]; then
+        # 计算下载速度
+        download_speed=$(echo "scale=2; (10000000*8)/(($elapsed_time)*100000)" | bc)
+        
+        # 如果下载速度小于 50Mbps
+        if (( $(echo "$download_speed < 50" | bc -l) )); then
+            # 从 ip_use.txt 删除下载速度小于 50Mbps 的 IP
+            sed -i "/$ip/d" ip_use.txt
+        else
+            echo "$ip has a download speed of $download_speed Mbps"
+        fi
+    else
+        echo "Download test for $ip failed with status $curl_status"
+    fi
+    echo "Finished download test for $ip"
+done < ip_use.txt
\ No newline at end of file