Various embodiments may relate to a drive circuit of an illumination device. The drive circuit has an output terminal connected to a load of the illumination device. The drive circuit includes a power supply, a boost control unit connected to an output terminal of the power supply, a main control unit connected to the boost control unit, and a load current control unit connected between the main control unit and the load, and including a switch unit. The switch unit includes a first sub switch unit, which is configured to switch according to a dimming control signal from the main control unit, and further includes a second sub switch unit connected to the first sub switch unit. The second sub switch unit is configured to be turned on in a situation where the first sub switch unit is turned on so as to turn off the first sub switch unit.