The PI control strategy based on disturbance observer is adopted in the single-phase inverter,namely the interference is completely suppressed by the equivalent compensation which is bring into the controller by the disturbance observer. The comprehensive analysis of this control strategy and the traditional PI control is given in theory, and the system is studied in MATLAB , besides, the control scheme is achieved in the single phase inverter platform based on DSP by using digital control algorithm. The simulation result and experimental result prove that the proposed scheme can achieve good dynamic and steady-state performance with better ability of harmonic suppression, compared with the traditional PI control, thus verifying the correctness of theoretical analysis, and giving a certain reference to other systematic deign.