Abstract: One of the most important goals in WSN research is to decrease energy consumption and maximize network life to meet application requirements. Therefore considering the energy efficiency of nodes in the networks has a very important theoretical and practical significance. This study presents a chain structure-based uneven cluster routing algorithm. In this algorithm, the node residual energy and regional node density are used as an ability of cluster-head competition, the nodes of big residual energy have great possibility of becoming the cluster head. The candidate cluster head calculates, according to the distance between the node and base station, the competition radius and constructs number of unequal size cluster. The size of cluster near the base station is smaller than that away from the base station. Cluster members organize into cluster by chain structure, the dynamic multi-hop routing transmit data is used by cluster-heads. The simulation results show that the new algorithm can effectively reduce network energy consumption, better balance the energy consumption of network nodes and prolong the network lifetime significantly.