In order to easily expand the DC microgrid capacity and enhance the system stability, the parallel system with bi-directional AC/DC converters is adopted to realize the energy exchange between the DC microgird and the utility grid. A power sharing strategy with low voltage deviation is proposed for the parallel system. By using the average DC-line current as the global variable and introducing the integral part, the accurate power sharing between converters can be achieved without the impact from line parameters. By adding the average output voltage proportional integral control, the deviation of DC bus voltage is diminished. The impact on the power control of the parallel system by the secondary ripple current is studied. And the band-stop filter is introduced to reduce the grid-connected current distortion rate caused by the secondary ripple current and voltage. The stability of converter parallel system is analyzed and the appropriate control parameters are given. Finally, the simulation proves the effectiveness of the proposed control strategy. This work is supported by National Natural Science Foundation of China (No. 51677059).