An exterior camera system and a cleaning method thereof are provided. The exterior camera system includes a base unit that is fixed to a vehicle, a housing rotatably coupled with the base unit, and an imaging device including a camera module and having at least a portion inserted into the housing to move in a longitudinal direction of the housing. A wiper is disposed on an inside surface of the housing to face the camera module, and a washer fluid nozzle is disposed adjacent to the wiper. A controller receives a video from the camera module to set a rotation angle of the housing based upon driving conditions of the vehicle and to adjust extension of the imaging device.