The boost-type single-phase inverter with active power buffer can effectively reduce the use of electrolytic capacitor and extend the lifetime of the circuits. In order to (i) buffer the power mismatch between the AC and DC terminals and (ii) regulate the DC current, simultaneously, the voltage of the buffering capacitor and DC current are directly controlled, which results in inaccurate control of AC power and complicated design of compensators. In this paper, a power decoupling control method, which controls the power of DC and AC terminals, is proposed for the boost-type single-phase inverter. With the proposed control method, the design of the compensators for the DC and AC terminals become easy and the dynamic responses of the boost-type single-phase inverter can be improved. The circuit operating principles of the inverter is firstly introduced. The design procedure of the proposed controller is provided. Simulation have been performed on a 110 V system to verify the effectiveness of the proposed controller.