In power electronic transformers, for the converters of the input and output stages of the high-frequency transformer connection, the existing modulation method consists of voltage, current vector calculation and duty cycle, making the control strategy too complicated. In this paper, a composite control application is proposed in the whole system. The composite controller consists of feed-forward decoupling control and intelligent predictive control. The feed-forward control is fully decoupled based on the cross-coupling potential in the PET system, and then the discrete model passed by the intelligent predictive control predicts the circuit variables, ensuring that the current reference of the AC output is closest to the estimate of the feed-forward term. And in the next sampling cycle, the most suitable switching state is selected to drive the power device. The simulation experiment is carried out on the different voltage amplitudes and load power changes between the input and output of the system. The simulation results show that the system can improve the steady-state performance and anti-interference ability, and get the unit power factor operation. The research shows that the proposed The correctness and effectiveness of the method.