To establish the two key in wireless sensor network is a basic security services, forming the basis other security services, such as authentication and encrypted. However, due to the sensor network resource constraints on to establish the two key not wireless sensor networks trivial tasks. The existing key, pre-alpha-ever scheme compromise node number and a minor part however influence key will increase quickly. As a result, a small compromise the number of node may affect the most adversaries. This paper proposes an improved key management wireless sensor network plan, take advantage of one-way hash function to alleviate the influence of compromise the sensor high sensor nodes. At the same time, this method does not affect the connection between neighboring sensor node.