A new trusted cluster-based is presented on the basis of the peculiarity of sensor network. The method is applied to LEACH protocol for enhancing security. The scheme supposes that network is composed of cluster nodes and sensor nodes. The cluster nodes response for managing sensor nodes and forwarding datagram. They also act as sensor nodes when the overlay rate of network is at level lower than given threshold. According to ward behavior of nods in cluster by collecting, reporting and verifying trust information, the method can ensure data transmission secure and prolong the survival period of whole network. Simulation experiment shows that the method is feasible and effective. The scheme can deal with incomplete and uncertain evidence so as to make up the defects of LEACH protocol.