In order to improve the automation degree and work efficiency of cartridge assembly system, a set of control system based on PLC was designed by combining with control system hardware. Analyze the application status of cartridge assembly system, and puts forward the improvement plan for the automation degree and work efficiency of the system. Analyze the functions of the control system according to the equipment debugging and production requirements. The hardware part of the control system is designed by taking PLC as the control center and touch screen as human-machine interface. From the overall design, PLC program design and human-machine interface design to complete the control system software design. The test results show that the system running is stable, parameters of cartridge meet the technical indexes, and the automation degree and work efficiency of the system are effectively improved.