The invention discloses a concurrent control process voltage compensating method of an energy storage system at the tail end of the power distribution network. The concurrent control process voltage compensating method includes steps of S01, disconnecting network combination point switches and operating the energy storage system in a V/F voltage source mode in the off-network state; S02, detecting whether terminal voltage of the power distribution network is recovered or not, if yes, acquiring the terminal voltage of the power distribution network, and calculating to obtain three-phase voltage amplitude average Ugrid; S03, acquiring microgrid terminal voltage of the network combination point switches and calculating to obtain three-phase voltage amplitude average value Umicro; acquiring in-place terminal voltage of the energy storage system and calculating to obtain three-phase amplitude average value Uabc; S04, compensating voltage reference to obtain voltage control reference value Uref, wherein Uref=Ugrid+(Uabc-Umicro); S05, forming voltage closed loops between the voltage control reference value Uref and terminal voltage Ua, Ub and Uc of the energy storage system and outputting output voltage of modulating waves controlling the energy storage system, wherein Ua is A-phase voltage amplitude, Ub is B-phase voltage amplitude and Uc is C-phase voltage amplitude. Operation stability of the microgrid system is improved.