An air conditioning system and a control method are provided. The air conditioning system includes: at least one heat exchanger (1, 2); and at least one control mechanism. Each control mechanism is connected to one of the at least one heat exchanger (1, 2) and is configured to control the corresponding heat exchanger to switch between a first working state and a second working state. The heat exchanger (1, 2) drains liquid when in the first working state and stores liquid when in the second working state.