Aiming at the problems of single grasping method and complex finger structure of the manipulator used in existing automobile and motorcycle assembly process, a three DOF mechanical finger with two sets of connecting rods was designed. A manipulator composed of three fingers was set up to carry out target grasping experiment. The experimental results show that the manipulator composed of the fingers can grasp various shape rules stably, and has good flexibility and dexterity. It provides reference for automobile and motorcycle assembly process.