Image forming apparatus, and method of controlling warming-up time of image forming apparatus

The invention provides an image formation device and a preheat time control method. In the image formation device, time reference is generally the base; after the preheat time of a fixing device is stated, when the temperature of a fixing component is probably lower than the setting temperature, bad fixing caused by power storage can be avoided. If the power of a fixing control device is set at 700, when 600 of the power is supplied to the fixing device after preparation, the power is lower than the necessary power. For example, the power generally supplied to the fixing device is 1200W, and the power actually supplied is 1080W (10 percent reduction), the time priority mode (time reference) is switched to the temperature priority mode (temperature reference); wherein the time priority mode judges whether the fixing device can fix according to the time from the preparation to the given time; while the temperature priority mode judges whether the fixing device can fix according to the standard that the temperat