A planar three degree of freedom (3DOF) serial manipulator was integrated and designed with the computer numercial control (CNC) machine tool. According to the space positions of the workpiece conveyor belt and the machine tool chuck, motion path planning of gripper center of the manipulator was made. Then set the motion time of each route, the dynamics simulation was conducted of manipulator in a complete cycle of loading and unloading workpiece with ADAMS software. Further, rotation angle, angle velocity and angle acceleration were calculated of large arm, small arm and gripper. When grabbing maximum mass of the workpiece, the driving torque required in three joints in the dynamic process was simulated. The simulation results show that method of integrated designing is correct, and can provide complete data reference for the selection of types of servo motor.