The work aims to design an automatic line for campus souvenir packaging based on the Dobot light-weight manipulator to solve the problems of high labor intensity, low production rate and poor consistency in manual packaging operations. First, each process of the automatic packaging line was analyzed to determine the critical path points of each process step, and plan the manipulator motion trajectory in each process step. Secondly, the Robotics Toolbox was used to establish a simulation model of the manipulator for motion simulation analysis. Finally, the visual motion virtual simulation was carried out by combining Matlab and Inventor. The motion simulation results showed that there was no sudden change in the angular displacement of each joint during the execution of the trajectory planning task, and the angular velocity and angular acceleration curves were smooth, which could ensure the smooth operation of the manipulator. The visual virtual simulation showed that the manipulator ran smoothly. It is proved that the motion planning of the manipulator in each process is feasible and can meet the requirements of each process step and packaging automation task.