Abstract: Aimed at solving the problem of double welding robots collision in the same workspace, this research presented a method of collision-free path planning based on assuming correction strategy and genetic algorithm. Envelope model of robot was established with sphere and cylinder, and the analytical expression of shortest distance between two robots was calculated in local coordinate system using space geometry principle. An assuming path was given by ideal constraint's condition, the planning of arc welding process and the shortest distance between solder joints. Fitness function was related to the quality of arc welding, the shortest distance of spot welding, the shortest distance between two robots, the range of joints. Genetic algorithm was used to search for safe configuration. Taking stud welding station an example, this paper did collision-free path planning and emulation experiments with MATLAB and DELMIA software. The method was proved correct and feasible, planning a quality and safe path for double robots.