The invention provides a bidirectional bootstrap power supply circuit and method and a power switch device driven by self power supply. The circuit comprises a bidirectional power taking module, a first
energy storage module and a second
energy storage module. The bidirectional power taking module is connected between the first power supply end and the second power supply end; the first
energy storage module and the second energy storage module respectively comprise a switching tube and an energy storage
capacitor, the switching tube is connected between the bidirectional power taking module and the first end of the energy storage
capacitor, the first end of the energy storage
capacitor is connected with a power supply output end, the second end is connected with a power supply end, and the power supply output end supplies power to driving signals of the bidirectional
switching power device; when a
potential difference exists between the two power supply ends, the circuit takes power from the high-
voltage end through the bidirectional power taking module, charges the corresponding energy storage capacitor by using the switch tube or the body
diode thereof, and establishes a driving
power supply voltage; when the power device is conducted and the potentials at the two ends are close, the
electric energy is bidirectionally transferred between the two energy storage capacitors. An external isolation power supply can be omitted, the power supply architecture of the bidirectional power device is simplified, and the cost is reduced.