Control method of air conditioning system and air conditioning system

The invention relates to the technical field of self-cleaning of air conditioners, particularly provides a control method of an air conditioning system and the air conditioning system, and aims to solve the problem that an existing air conditioning system is difficult to classify filth blockage of a heat exchanger for self-cleaning. In order to achieve the purpose, the control method of the air conditioning system comprises the steps that the pressure difference of air pressure on the two sides of a heat exchanger is obtained; determining the filth blockage degree of the heat exchanger according to the pressure difference; and determining a self-cleaning mode according to the filth blockage degree of the heat exchanger. The self-cleaning mode is determined according to the filth blockage degree of the heat exchanger, self-cleaning is conducted in an energy-saving mode under the condition that the filth blockage degree of the heat exchanger is low, cleaning time can be saved, cleaning energy consumption can be