Abstract: This paper proposes an improved midpoint clamped HERIC topology based on the HERIC circuit topology. This topology adds two switching tubes between the midpoint of the DC input capacitor of the photovoltaic inverter and the main circuit bridge arm.The voltages at the bridge arm and the voltage value is effectively clamped which is half of the input capacitor voltage. The total commonmode voltage remains unchanged to achieve the purpose of suppressing leakage current. Simulations and experiments verify that the proposed circuit has the characteristics of high efficiency and good suppression.