Method for switching power supply of fast switching device and fast switching device

The invention provides a power supply switching method of a fast switching device and the fast switching device, a power distribution system comprises the fast switching device and at least two power supplies, the power supply which is currently supplying power serves as a working power supply, and the other power supplies serve as standby power supplies. The quick switching device is used for triggering the switching between the working power supply and the standby power supply under the condition that the power distribution system meets the condition, and the method comprises the following steps: receiving a target mode which is used for triggering the quick switching device to start to judge whether to execute the power supply switching operation or not, the target mode is determined according to the real-time working condition of the power distribution system; storing the target mode; and if it is recognized that the quick switching device is started in the target mode, whether power switching operation i