Compression device, air conditioner and control method and control device

The invention provides a compression device, an air conditioner and a control method and device of the air conditioner. The compression device comprises a shell, an evaporation chamber, a motor cooling chamber and a condensation chamber are formed in the shell, the evaporation chamber and the condensation chamber are communicated through a first channel, the motor cooling chamber and the condensation chamber are communicated through a second channel, the condensation chamber is provided with a first refrigerant outlet, the motor cooling chamber is provided with a first refrigerant inlet, and the first refrigerant inlet is provided with a second refrigerant outlet. The evaporation chamber is provided with a plurality of refrigerant inlets and outlets, the refrigerant inlets and outlets comprise second refrigerant inlets, and the first refrigerant outlet is configured to be capable of communicating with the first refrigerant inlet and the second refrigerant inlet; the motor is mounted in the motor cooling chamb