The invention relates to a power supply circuit and a power supply device, and the power supply circuit comprises a charging circuit, a boost circuit and a buffer circuit, wherein the charging circuitis connected with the buffer circuit through the boost circuit, and the output end of the buffer circuit is connected with a distribution automation terminal; the buffer circuit comprises a buffer battery pack and a buffer capacitor; the output end of the booster circuit is connected with the anode of the buffer battery pack, the cathode of the buffer battery pack is grounded, and the output endof the booster circuit is grounded through the buffer capacitor. The output end of the charging circuit outputs a voltage, and the voltage value of the voltage is increased through the booster circuit. The voltage outputted by the boost circuit is used for charging the buffer battery pack and the buffer capacitor, and the output end of the buffer battery pack provides a stable working voltage. Thebuffer capacitor needs to discharge after the buffer capacitor is fully charged, and an instantaneous large current is provided when the buffer capacitor discharges, so that the remote control function of the power supply device to switch on and switch off the switch cabinet is realized.