Abstract: The direction of sound source target can be currently obtained through the research on sound source localization of mobile robots; however,the accurate distance information cannot be obtained. In view of this problem,a method based on active movement of mobile robot is put forward to get the distance information of sound source target,and a method based on the particle swarm optimization algorithm is established to get the optimal detecting point. Simulation results show that this method is feasible and effective. Moreover,the test in the indoor environment shows that the mobile robot can reach the optimal detection point through active movement and obtain the distance information of sound source target.