Provided is a method for controlling a magnet type fan clutch, by which method engine performance, fuel efficiency, engine life, vehicle acceleration capability and other properties of a magnet type fan clutch can be further improved and its fan noise can be further reduced. This method is adopted for controlling a magnet type fan clutch which includes a magnet coupling, an electromagnetic clutch combined with the magnet coupling to control the on / off switching of the magnet coupling, and a fan attached to the magnet coupling. The control method is characterized in that the electromagnetic clutch is turned on or off based on at least one signal of temperatures of radiator coolant, engine oil and transmission oil, a vehicle speed, a rotational speed of an engine, compressor pressure of an air conditioner, and an on / off signal of the air conditioner, etc., so as to control the rotation of the fan.