The instantaneous output power of the two-stage single-phase inverter contains the pulsating power whose frequency is twice as much as the output voltage frequency. For this reason, the secondary ripple current exists in the input of the front-stage DC/DC converter. The control loop optimization of the pre-stage DC/DC converter is an effective and low-cost method to solve this problem. The equivalent circuit models of single loop control and double loop control are given through loop equivalence. Based on the concept of virtual impedance, the functions of voltage outer loop and current inner loop in secondary ripple current transfer process are analyzed. On this basis, the suppression principles of the conventional control strategies are explained and summarized, the limitations of existing control strategies are pointed out, and two optimization schemes are given. Finally, a 1.5 kVA two-stage single-phase inverter prototype is built for simulation and experimental verification, which verifies the feasibility of the analysis method and the effectiveness of the control strategy optimization.