In wireless sensor network (WSN), how to realize key distribution among sensors with lower computational cost is always an interesting issue. A key distribution scheme based on quantum entanglement exchange is proposed. A hierarchical network based cluster is designed, and the key distribution among the base station and cluster head, cluster head and terminal nodes is realized by broadcast and peer-to-peer communications. The entangled particle distribution is carried out at the base station, and the entanglement exchange is realized. The cluster heads and terminal nodes require only simple measurement operation. The proposed scheme can effectively reduce the computation amount, storage and energy consumption of each node, and improve performance of the whole wireless sensor network.