With the rapid development of information technology, online office and study has been applied by more and more colleges and universities, but the convenient off-campus access has brought a great threat to the network security. In order to solve this problem, this paper proposes an efficient hierarchical management balancing strategy for complex VPN under hierarchical protection 2.0. Through the process design of VPN, unified identity authentication and reverse proxy, the practical case of this strategy has been realized. The network security level of users has been significantly enhanced. In 2021, our school won the title of excellent defensive unit in the offensive and defensive exercises held by Hunan Provincial Public Security Department.