In order to achieve reasonable load current distribution and nondifference regulation of bus voltage in shipborne DC microgrid energy storage system, an autonomous current sharing strategy based on the convergence of charge (SoC) of energy storage state was proposed. This strategy added a compensation outer loop on the basis of conventional droop control to adaptively adjust the load current and reference voltage by constructing a SoC convergence function in the loop, so that the load current was distributed reasonably with the dynamic equalization of the SoC and maintained a higher bus voltage level. The proof of SoC convergence was given in this paper, and the selection rules of related parameters were analyzed. Additionally, a sparse communication network architecture was built to reduce the communication pressure of the energy storage system, and the dynamic average consensus algorithm was used to estimate the global average SoC and made it converge stably. Finally, a StarSim hardware in the loop experimental platform was built, and the results show that the proposed strategy can achieve the control objectives of state of charge balance, load current sharing and DC bus voltage stability.