Mobile wireless sensor networks （MWSNs） support the mobility of nodes， and face more complex security challenges. It is difficult to prevent attackers from launching some extremely destructive attacks， such as node replication attacks and sybil attacks. This paper proposes a safe and efficient key management method under the mobile heterogeneous wireless sensor network model. The proposed method adopts the elliptic curve cryptography encryption algorithm to realize the safe upload of mobile node location information to the base station， and uses the message authentication code based on key hash to realize the identity authentication of the message source. The base station performs statistical analysis on the collected location information of the mobile node to assist in completing the identity authentication and session key establishment between the fixed node and the mobile node. Experimental results show that the proposed method saves network resources during the key establishment process， and can effectively defend against attackers from launching replay attacks， node replication attacks， and sybil attacks， thus enhancing network security.