Abstract: To solve the optimizing problem of the path planning of robot with eleven degree-of-freedom, a multi-object mathematical model and solution plan has been proposed and analyzed. Using genetic algorithm as optimizing method, a adapive degree function was built.The suitable parameter was obtained through lots of practices.The genetic algorithm procedure was designed and realized. Based on this algorithm, optimizing experiments were carried out based on typical space transversal weld by using under 3 degreeof-freedom gantry and 6 degree-of-freedom robot.Results of experiments indicate that the suitable solution can be quickly found through the algorithm.This algorithm was simulated and also loaded to robot controller to do welding experiments.And the results show that robot joints move steady under the best position of robot placement and good welds have been acquired.It shows this method is correct and feasible.