The invention belongs to the technical field of power electronics, particularly relates to a DC-AC three-port converter, and also relates to an alternating current side current-sharing control methodof the DC-AC three-port converter. An internal phase-shifting angle and an external phase-shifting angle between bridge arms are controlled through direct-current bus current closed-loop regulation and alternating-current side current-sharing loops and decoupling compensation thereof, so that the current sharing control of the system power control and the alternating-current side current is realized. Power transmission direction control and power transmission size control between a direct-current side power supply and an alternating-current side power supply can be realized; and the balance ofthe alternating-current side current can be realized when the circuit parameters have differences; when the alternating-current side two-group frequency converters work normally, the system power level can be improved; and when one group suffers from faults, the other group works continuously, so that fault-tolerant capability of the system can be improved.