Industrial robot is more and more widely applied in all fields of industries, among which the loading and unloading is an important function. Aimed at requirements of the automatic loading and unloading of bent axle, the three dimensional (3D) model of loading and unloading robot system was set up. Based on SolidWorks Motion, holding stability of bent axle was simulated and studied. The simulation result shows that on the certain condition of limited time and limited space, through selected a better control of robot program and the clamp mode of V type finger, the holding stability of bent axle by the robot during loading and unloading process is improved and guaranteed. The study provides a theoretical basis for the optimization of robot teaching program. 