The invention provides an alternating-current rapid switch device and a control method thereof. The alternating-current rapid switch device comprises a bidirectional conduction branch circuit, a forced transfer branch circuit and a charging power supply, wherein the bidirectional conduction branch circuit is used for realizing bidirectional conduction of an alternating-current line work current; the forced transfer branch circuit is used for transferring a current of an alternating-current line in the bidirectional conduction branch circuit to the forced transfer branch circuit and reducing the current which is transferred to the alternating-current line of the forced transfer branch circuit to a zero point; and the charging power supply is used for charging a capacitor in the forced transfer branch circuit. In the invention, millisecond-grade conduction and turnoff of the alternating-current rapid switch device can be realized, and conduction and turnoff time can reach 1ms; a full-bridge module adopts an IGBT, an integration utilization rate is high, and through using a controllable characteristic of the IGBT and reverse voltage resistance and current resistance levels, high frequency conduction and turnoff control of the alternating-current rapid switch device are realized. In the technical scheme, the charging power supply used for charging the capacitor in the forced transfer branch circuit adopts a direct current power supply, controllability is high and device losses are small.