Due to the nonlinear characteristics of PWM rectification, the traditional PI control of the single-phase power electronic transformer rectification stage is more sensitive to the parameters, but the sliding mode variable structure control has strong robustness to disturbances and parameters. So, the dq current decoupling method was used to construct a sliding mode controller. A 3-unit cascaded module H-bridge rectifier model was built and simulated in the simulation software Matlab/Simulink. Compared with the traditional PI control, the results showed the effectiveness and superiority of the adopted method.