Aiming at the problem that the film tension control system of food packaging machine has the characteristics of multi-interference, time-varying and non-linearity, and the traditional PID is difficult control, a fuzzy fractional PID film tension control system is designed. Using expert knowledge and mature experience, combined with fractional order control, the control rules of five parameters of fractional order PID are designed, and the on-line real-time tuning of fractional order PID parameters is realized, which improves the precision and stability of bag film tension control. With PLC and touch screen as the core and TIA protal as the development platform, the hardware design, network configuration and program design of the control system are completed, and the control system is upgraded. The simulation results show that the fuzzy fractional PID controller has the advantages of fast response speed, good robustness of model mismatch and strong anti-interference ability. The control system can meet the requirements of precision and stability of tension control of packaging machine bag film.