Aiming at the problem of direct current component injection in traditional non-isolated inverter that connected to the grid, the reason of the DC component of a typical single-phase full-bridge inverter is analyzed. A HERIC inverter is introduced,and the structure of HERIC inverter itself has a certain isolation during freewheeling state. In order to further eliminate the DC component under the inverter operating condition, a closed-loop control strategy is proposed to suppress the DC component. By connecting a series of virtual resistors with infinite gain to the DC component at the inverter output port, DC component suppression. A 400V / 20A inverter grid-connected system is designed. The scheme proposed is verified through simulation experiments. The results show that this scheme has a good performance in DC component suppression.