Abstract: An increasing number of Peer-to-Peer (P2P) applications are appeared.The defect of P2P network which causes several security problems must be in focus.In this paper,a model of trusted P2P network will be introduced,which integrates the security mechanisms about integrity measurement,authorization, authentication and encryption.It can make a good security performance on centralized topology P2P network and establish the foundation of further P2P network application.