A power supply device and a booster circuit for a power supply device. The booster circuit includes an access terminal configured to access a direct current voltage from a battery pack, a transformer group electrically connected to the access terminal so that the accessed direct current voltage is boosted to a predetermined voltage by the transformer group, and a rectifier bridge electrically connected to the transformer group to convert the predetermined voltage into a high-voltage direct current after pulse rectification. The transformer group includes a first transformer including a first primary side and a first secondary side and a second transformer including a second primary side and a second secondary side. The power supply device disclosed is compact in structure and convenient to carry and can output an alternating current.