Electric vehicle air conditioning system and control method therefor

The invention aims at providing an electric vehicle air conditioning system which can save space and a control method therefor. The air conditioning system comprises a power supply, a power supply device, a compressor, a condenser, an evaporator, an air conditioning controller and a pipeline assembly including a vent pipe; the power supply device drives the compressor to work; the key point is that the power supply device is an electric motor used for providing the driving force for a power system of an electric vehicle, and the electric motor drives the compressor to work by a transmission system controlled by the air conditioning controller, and the electric motor and the air conditioning controller are respectively and electrically connected with a finished vehicle controller of the electric vehicle. The air conditioning system is not needed to be provided with the electric motor specially used for an air conditioner, so as to occupy small space; furthermore, only when the value of state of charge (SOC) of the battery is higher than liminal value of state of charge (SOCL) of the battery and the electric motor runs, the air conditioning controller can control the transmission system to transmit the power of the electric motor into the compressor, and the air conditioner works; therefore, normal driving of the electric vehicle is not affected.