Control method and device for air conditioning system

The invention belongs to the technical field of air conditioning, and particularly relates to a control method and device for an air conditioning system. According to the control method and device for the air conditioning system, all temperature parameters of the system after defrosting are acquired, the opening degree of operation of an electronic expansion valve is adjusted timely according to indoor temperature differences delta TIN and outdoor temperature differences delta TOU, the phenomenon of oil blockage of an expansion valve after low temperature defrosting of new refrigerant air conditioning systems such as R290 is effectively avoided, the using comfort of the new refrigerant air conditioning systems is improved, the service life of a compressor and the system is prolonged, and a reference basis is provided for better matching new refrigerants for studying novel compressor engine oil in the future.