Split-phase input control method for rapid power supply switching device

The invention discloses a split-phase input control method for a rapid power supply switching device. The method comprises the following steps: acquiring working states of a main power supply and a standby power supply; if the main power supply breaks down, a trigger signal of a first thyristor module connected with the main power supply is immediately blocked; judging whether the standby power supply meets a quasi-synchronous input condition or not; if not, judging whether the phase angle corresponding to the line voltage difference between the stand-by power supply end AB phase and the load end AB phase is 90 degrees or not, or judging whether the phase angle corresponding to the phase voltage difference between the stand-by power supply end A phase and the load end A phase is 60 degrees or not; if yes, an A-phase thyristor and a B-phase thyristor of a second thyristor module connected with the standby power supply are triggered to be conducted; and a C-phase thyristor of the second thyristor module is trig