Aiming at the problems that hierarchical routing LEACH protocol has uneven distribution of clusterhead and each cluster head rotation is carried out in the whole network which will result in excessive energy consumption， and the problem that energy consumption is not balanced when ant colony algorithm is applied to LEACHprotocol to establish a multi-hop routing. Firstly，we use the method that divides the net nodes，take the node residual energy as reference factors and select the cluster head node in turn within the region to make an improvement. Then we improve the ant routing algorithm by introducing the energy of the nodes into the transition probabil-ides and pheromone updating formula and use the improved algorithm to establish the optimal path from the clusterhead node to sink node multi-hop routing. Experiments show that compared with LEACH protocol，the improvedprotocol reduces and balances the overall energy consumption and extends the life cycle of a wireless sensor network.