Aiming at the problems of long path length and more turning points of mobile robots in the flexible assembly process of circuit breaker, a path optimization method combining BAS algorithm and PSO algorithm is proposed. By combining the individual update method of beetles with group learning, the adaptive step size decay strategy and the dynamic weight change strategy are adopted to realize the optimization of global path planning. In order to verify the effectiveness of the BSO algorithm, three different test functions are used to compare the performance and the simulation map, and finally the algorithm is applied to the actual map through ROS. Experimental results show that compared with GA-PSO algorithm, AIW-PSO algorithm and BAS algorithm, the optimization efficiency of path length is increased by 7.7%, 14.8% and 12.5%, and the optimization efficiency of the number of turns is increased by 25%, 57.1% and 40%, respectively. In summary, the fusion algorithm proposed in this paper can effectively solve the efficiency problem in the assembly process and improve the efficiency of the flexible assembly line of the circuit breaker.