This article aims at the growing demand for efficiency and safety in the logistics industry for truck loading and unloading scenarios, and designs a rope-driven seven-degree-of-freedom robotic arm for logistics loading and unloading. Firstly, through the demand analysis, a mechanical arm structure design suitable for the truck loading and unloading scenario is proposed, and based on its structural characteristics, its kinematic model is established. Then, the control system of the mechanical arm is designed, and singular points are processed to ensure the stability and reliability during the loading and unloading process. Finally, using MATLAB, the kinematic model of the robot is established, and the effectiveness of the control system is verified in the Vrep simulation environment. The results show that the system can accurately and efficiently complete the loading and unloading tasks, improving work efficiency.