A three-phase AC power switching circuit comprises a three-phase AC power, a first transfer switch and a second transfer switch; a first phase AC power and a second phase AC power of the three-phase AC power are selectively output by the first transfer switch; when the first phase AC power works normally, the first transfer switch outputs the output voltage of the first phase AC power, and the output voltage of the first transfer switch and a third phase AC power of the three-phase AC power are selectively output by the second transfer switch; when the third phase AC power works normally, the second transfer switch outputs the output voltage of the third phase AC power. The three-phase AC power switching circuit realizes the automatic switching function of the three-phase AC power by two transfer switches and maintains the steady voltage output when the first or the second phase AC power of the three-phase AC power is abnormal.