Abstract: In order to improve the assembly efficiency of the opening and closing hood of the EMU reduce the labor intensity of the workers, a special chuck fixture is proposed for the irregular shape of the opening and closing hood and the easily damaged material. The clamping device can adapt to the irregular shape of the opening and closing hood, allow the processing error of the open and close cover, and realize the automatic assembly task with the manipulator. In the electrical design implement a variety of anti - fall scheme to ensure the safety of the system. Through the force analysis of each sucker, the vulnerable position of the sucker fixture is determined by the finite element analysis method to guide the later maintenance of the sucker fixture. Analyze the deformation of the open cover to avoid damage to the workpiece during installation. The sucker clamp greatly shortens the assembly time and reduces the assembly difficulty, and has achieved good practical application effect.