Aiming at the problem of time-consuming and labor-intensive routing path design in the cable layout design of complex electromechanical products, an automatic routing technology for complex electromechanical product cables based on multi rules particle swarm algorithm was proposed. Firstly, the cable routing environment of electromechanical products was analyzed, and the routing path was abstracted into a sequence of points to complete the definition of cable routing space. Through pose transformation, the problem of difficult interference detection between wiring paths and parts in electromechanical products was solved. In order to make full use of the wiring space, the particle multiple rules were introduced into the particle swarm optimization algorithm. By using particle number, multi-scale collision detection, adjacent waypoint replacement method and fourth-order quasi-uniform B-spline curve method, the problem that the routing environment is complicated and the optimal solution cannot be obtained was solved, and the searching ability, solving speed and routing quality of the algorithm were improved. Through simulation analysis and comparison with other algorithms, the superiority of the algorithm is proved. The example proves that the proposed method can search feasible paths efficiently during routing. The generated routing paths do not interfere with parts in three-dimensional space, and there are no mutation points in the path fairing, which provides a new idea for the automatic routing of complex electromechanical products.