An air conditioning system applicable to a vehicle, wherein the air conditioning system comprises an air conditioning controller, an electronic expansion valve and an electric control component for controlling a motion of the electronic expansion valve; wherein: the air conditioning controller is a control center of the air conditioning system; the air conditioning controller is configured to receive and parse at least one of a control signal from a vehicle system or a control board, and input information from the vehicle system or the control board, and send a parsed control signal; the air conditioning controller is configured to receive at least one of input information from a main control board of the air conditioning system and sensor information, calculate a control signal, by using a preset control program for the electronic expansion valve stored in the air conditioning controller, based on the input information or the sensor information and/or feedback information stored in the air conditioning controller, and send the control signal; and the electronic control component is configured to convert the control signal into an energy with a motion signal by which the motion of the electronic expansion valve is controlled; the electronic expansion valve is configured to adjust a flow of refrigerant and/or turn on/off a flowing passage for the refrigerant in a cooling system of the air conditioning system; and the air conditioning system is configured to send different motion speed control signals according to different operation states of the air conditioning system, to control the electronic expansion valve to move at different motion speeds, characterized in that the electronic expansion valve is controlled to perform following procedures: an initialization procedure, a pre-adjustment procedure, a negative feedback procedure and a quick turning-off procedure; the different motion speed control signals include a control signal for the initialization motion and a control signal for the initialization motion speed, a control signal for a pre-adjustment target opening and a control signal for a pre-adjustment motion speed, a control signal for the target opening and a control signal for the negative feedback adjustment motion speed, and a control signal for fully turning-off and a control signal for a maximum motion speed. the air conditioning controller is a control center of the air conditioning system; the air conditioning controller is configured to receive and parse at least one of a control signal from a vehicle system or a control board, and input information from the vehicle system or the control board, and send a parsed control signal; the air conditioning controller is configured to receive at least one of input information from a main control board of the air conditioning system and sensor information, calculate a control signal, by using a preset control program for the electronic expansion valve stored in the air conditioning controller, based on the input information or the sensor information and/or feedback information stored in the air conditioning controller, and send the control signal; and the electronic control component is configured to convert the control signal into an energy with a motion signal by which the motion of the electronic expansion valve is controlled; the electronic expansion valve is configured to adjust a flow of refrigerant and/or turn on/off a flowing passage for the refrigerant in a cooling system of the air conditioning system; and the air conditioning system is configured to send different motion speed control signals according to different operation states of the air conditioning system, to control the electronic expansion valve to move at different motion speeds, characterized in that the electronic expansion valve is controlled to perform following procedures: an initialization procedure, a pre-adjustment procedure, a negative feedback procedure and a quick turning-off procedure; the different motion speed control signals include a control signal for the initialization motion and a control signal for the initialization motion speed, a control signal for a pre-adjustment target opening and a control signal for a pre-adjustment motion speed, a control signal for the target opening and a control signal for the negative feedback adjustment motion speed, and a control signal for fully turning-off and a control signal for a maximum motion speed.