防火墙技术是保护网络安全的一种重要手段，代理服务器是防火墙的关键技术之一，其效率与其安全防护能力同样不容忽视，文中叙述了一种高效防火墙系统的实现原理。 Firewall technology is an important means to protect the network security. Proxy server is one of the key technologies of firewall. Its efficiency and its security protection capability should not be ignored. The article describes the principle of an efficient firewall system.