To provide a side brush drive control device for a car-washing machine capable of reducing the generation of scratch and hit mark on a vehicle body without making rotation torque of the side brush excessive when the side brush is abutted on the vehicle body.

The side brush drive control device for the car-washing machine is provided with a speed instruction part 51 for setting an instruction value of rotation speed of a drive motor 15; a speed control part 52 for controlling the rotation speed of the drive motor 15 so as to make the speed instruction value set at the speed instruction value 51 and the detected rotation speed of the drive motor 15 coincident; an abutment/leaving detection part 53 for comparing the rotation speed of the drive motor 15 with the speed instruction value, detecting abutment or leaving of the side brush 12 relative to a vehicle, producing a current restriction value of the drive motor 15 at the abutment and outputting it to a current restriction part 53; and a current restriction part 54 for controlling the drive of the drive motor 15 so as to make the detected drive current of the drive motor 15 coincident with the current restriction value.