The classical routing protocol Low Energy Adaptive Clustering Hierarchy (LEACH) adopts adaptive clustering algorithm, and cluster heads communicate directly with base station. The longer the distance, the more energy will be consumed in the way of single-hop transmission. Eventually, the whole network will be out of work. An advanced routing protocol based on energy optimization named ANT-LEACH was proposed, which adopted the strategy of combining the Ant Colony Optimization algorithm with routing process of cluster head nodes. This protocol introduced lead force function to improve the ant transition probability and the pheromone updating rule. And it would take full account of the cluster head nodes' residual energy, make sure to find the optimal path between cluster heads and base station, and change the single-hop transmission to multi-hop. The simulation results demonstrate that this algorithm can effectively reduce nodes' energy consumption, prolong the lifetime of whole network and ensure load balance.