Abstract: The fundamental theory,key technology and prevailing solution in the security fields were analyzed.A new firewall architecture was discussed in detail.Compared with traditional firewall,it has markedly advantage in generality,transparency and authentication.Firewall,as a comprehensive security protection system,does not mean a single technology or product.Actually,its functionality is the result of cooperation of all basic security components.Particularly,authentication,as the basis of other security function,has specfic importance.We designed and developed a practical security protection system suitable to deployment on the edge of local campus network,which combined the advanced security characteristic of strong authentication mechanism and general proxy firewall architecture.