In order to solve the problems in wireless sensor networks, such as node failure and losing of master key, a secure communication model based on secret sharing in wireless sensor networks is presented in this paper. In this model, with the secret sharing mechanism, the master key is divided into n parts which are distributed to the council nodes. Accordingly the council nodes can protect the master key, distribute keys to the nodes in the domain, periodically monitor the key node to avoid failure and improve the date output rate.