Abstract: To solve the problem of automatic assembly sequence planning of flexible cables in complex electromechanical products, a new method was proposed for assembly sequence planning of flexible cables based on improved particle swarm optimization. Firstly, the constraint conditions of cable assembly were determined. On this basis, a mathematical model of cable assembly sequence planning was established with priority of cable assembly, cable length, diameter, bending radius and number of branches as comprehensive optimization objectives. Then the standard particle swarm optimization algorithm was discretized to make it suitable for assembly sequence planning. On this basis, the initialization of assembly sequence and the search strategy of the algorithm were improved respectively. Finally, the proposed algorithm was applied to the cable assembly sequence planning process of a certain type of satellite structure plate, verifying its feasibility and computational efficiency.