The invention relates to fan control method and device. The method comprises the following steps of: arranging an influence factor of a fan group according to the influence degree to a temperature-sensitive region from the fan group in the fan control device, wherein the fan group comprises at least one fan; acquiring the temperature of the temperature-sensitive region by the fan control device when the fan group runs; and regulating the rotation speed of the fan group by the fan control device according to the influence factor and the temperature difference value when the temperature exceeds the normal temperature range. The method and the device can effectively provide the cooling efficiency of the fan.