Aiming at the problems of large common mode current and low efficiency of existing transformerless single-phase grid-connected photovoltaic inverters, a novel transformerless single-phase grid-connected photovoltaic inverter topology is proposed. In this novel topology, two freewheeling diodes are added to the single-phase full-bridge inverter, and the ac side filter inductors are moved to the lower bridge arms of the inverter, so that the common mode voltage remains unchanged during the switching period and the common mode current is effectively suppressed. Meanwhile, MOSFET is used as the high frequency switching tube, IGBT is used as the power frequency switching tube, and additional switching tubes are avoided. Therefore, the overall system losses are reduced. Finally, the effectiveness of the novel topology to suppress the common mode current is verified through the simulation and experiments of 3 kW system.