Quick frosting cold air prevention self-cleaning control method and system for air conditioner

The method comprises the steps that a four-way valve is closed, a refrigeration state is started, fresh air temperature and humidity and indoor temperature and humidity are detected, fresh air dew point temperature and indoor dew point temperature are compared, and the opening degree of a first air valve assembly is adjusted according to the comparison result; the compressor is controlled to operate at the frosting frequency, and the exhaust superheat degree of the compressor is obtained; when the exhaust superheat degree is within the set superheat degree interval, the input pressure of the compressor is detected in real time; when the input pressure is in the set pressure interval, the opening degree of the second air valve assembly is adjusted, the opening degree of the current throttling device and the opening degree of the first air valve assembly are determined, and after operation is maintained for a set first time period, a compressor is controlled to be subjected to frequency reduction; and the four-