Air conditioning system, control method thereof and storage medium

The invention discloses an air conditioning system and a control method thereof and a storage medium, the air conditioning system comprises a master unit and a cold storage sub-unit, a sub-cabin is arranged at the lower part of the master unit, the master unit forms an exhaust channel communicating the sub-cabin with the outside, and when the cold storage sub-unit is located in the sub-cabin of the master unit, a hot air exhaust port of the cold storage sub-unit communicates with the exhaust channel; the control method comprises the steps that when the cold storage sub-machine is started, the internal temperature of the cold storage box in the cold storage sub-machine is obtained; and when the internal temperature is larger than or equal to the preset temperature and the cold storage sub-machine is located in the sub-cabin, the cold storage sub-machine is controlled to execute the cold storage action. When it is detected that the ice storage amount is insufficient and the cold storage sub-machine is located i