Abstract: Aimed at the situation of the poor control effect of the traditional PID used in the multiplexed output converter，the design and simulation of the system were proposed by introducing the fuzzy control into the PID control strategy. In this paper，taking two-transistor forward converter for example，PID controller and fuzzy PID controller were designed，the system model was created in MATLAB and the corresponding simulation was carried out. The simulation results showed that the fuzzy PID control was better than the traditional PID control system，and got better steady-state and dynamic effects. The fuzzy control rules were used for the parameter tuning of PID，it had good control performance and strong robustness to the control of switching converters.

Key words: fuzzy control, PID control, two-transistor forward converter, two-channel output