The invention provides a power supply circuit which comprises a rectifying circuit, a current-limiting resistor serially connected with a positive output end of the rectifying circuit, and a quick starting module, wherein the quick starting module is provided with a switch element, a charge resistor, a capacitor and a biasing resistor, a first end of the switch element is connected with a terminal, which is close to the positive output end of the rectifying circuit, of the current-limiting resistor, a second end of the switch element is connected with a terminal, which is close to a load end, of the current-limiting resistor, the first end and the second end are connected/disconnected on the basis of a voltage between the first end and a third end as a control end; one end of the charge resistor is connected with a third end of the switch element; one end of the capacitor is connected with the other end of the charge resistor, the other end of the capacitor is grounded; two ends of the biasing resistor are respectively connected with the first end and the third end of the switch element.