The LEACH algorithm is a typical single-hop clustering routing algorithm for wireless sensor networks. Aiming at mending the shortcomings of LEACH, this paper proposes an improved energy-efficient clustering multi-hop routing algorithm which uses the analytic hierarchy process to determine the weight coefficients of the four factors:the node degree, the communication distance between nodes, the residual energy of nodes and the distance from node to base station. The four factors are introduced in the cluster election after each round of the election of cluster head. The genetic algorithm is used to find a traversal of all cluster head node and the base station of the optimal path. The algorithm realizes the function of transmitting data from the cluster head to base station by multi-hop communication mode. The experimental results show that the proposed algorithm has better performance than CECA, LEACH-GA and LEACH algorithm in the life cycle of the network, the network energy consumption and the balance of energy. It has achieved the balance in energy and has prolonged the network lifecycle.