In view of the flaw exhibited by the firefly algorithm in cases where it is liable to fall into the local optimum, some improvement has thus been made about it by changing the search strategy of the firefly algorithm, which helps to improve its optimization ability. As for the path planning of mobile robots, an optimal path planning has been achieved by adopting an improved firefly algorithm. The theoretical and experimental results have verified the effectiveness of the improved algorithm, which can meet the requirements of mobile robot path planning.