The invention discloses an automobile air conditioner heating method which comprises the steps that on the premise that the power-on state of an automobile is ON, the air conditioner required strengthis calculated by collecting air conditioner settings of a user, and meanwhile whether heating is conducted or not is judged in combination with the collected engine water temperature and evaporator air outlet temperature; signals of in-vehicle temperature, in-vehicle humidity, out-vehicle temperature and sunlight intensity are collected, a front bumper dew point temperature and a front bumper inner wall surface temperature are calculated for judging a fogging risk; in addition, VCU power information is collected to judge whether PTC is allowed to be started or not; meanwhile, the vehicle speed serves as input of a calculation model, and the compensation effect of the vehicle speed on external circulation air intake is considered. And the information is integrated to obtain the temperatureair door opening degree, the air outlet mode, the air blower gear, the internal circulation proportion, the PTC power, the water pump duty ratio and other outputs in the state. On the premise of ensuring that the front gear is not fogged, the internal circulation proportion is increased as much as possible, so that the power consumption of electric appliances such as a PTC, an air blower and a water pump is reduced, and the purpose of saving energy is achieved.