The invention discloses an automatic air conditioner HVAC assembly device. The device comprises an air conditioner controller, an air conditioner control box, actuating equipment and a signal sensingmodule; an entity key value on the controller is collected, after logical processing is conducted, a logical signal is transmitted to an air conditioner control box in an LIN signal mode, and meanwhile the air conditioner controller lights a response indicator light as needed; the air conditioner control box receives an air conditioner controller instruction through an LIN communication bus, converts the instruction to be an air conditioner control state and transmits the control state to DVD in a CAN bus mode, and the DVD displays the current air conditioner state; the actuating equipment isused for conducting action according to the LIN signal instruction of the air conditioner control box; the signal sensing module is used for collecting an external environment state and transmitting the external environment state into the air conditioner control box. Accordingly, by monitoring temperatures of all air openings in real time, conversion resistance value is transmitted to an air conditioner ECU system for operation, starting and stopping of a compressor are controlled, and the human body comfort and fuel economical efficiency are greatly enhanced.