The invention discloses a control method of automobile heat pump air conditioner, which comprises the following steps: 1. After the parameters of the evaporator are normalized, inputting the parametersinto a first BP neural network to obtain the degree of superheat Delta Te of the outlet of the evaporator, the heat exchange quantity Qe of the evaporator and the heat exchange quantity Qair of the air side of the evaporator; At that same time, normalizing and inputting the parameter of the condenser into the second BP neural network to obtain the degree of subcooling Delta Tc of the condenser outlet, the heat exchange quantity Qc of the condenser and the heat exchange quantity Qair, c of the air side of the condenser; 2, calculating the heat exchange Delta Q of the heat pump air conditionerto be adjusted; 3, making clustering analysis of the heat exchange Qneed which the heat pump air condition system needs to provide to the occupant cabin, the air side heat transfer Qair of evaporatorand the heat transfer delta Q of heat pump air conditioning system, the total power of heat pump air conditioning system is minimized by adjusting the opening of electronic expansion valve, the duty ratio of cooling fan outside the vehicle, the duty ratio of cooling fan inside the vehicle and the rotational speed of compressor. The control method of the automobile heat pump air conditioner provided by the invention has the advantages of fast response speed and good control of energy consumption.