The invention provides a screw type unit which comprises a first heat exchange system, a second heat exchange system and an electrical control box. The first heat exchange system comprises a first compressor, a first heat exchanger, a second heat exchanger and a first throttling gear. The second heat exchange system comprises a second compressor, a third heat exchanger and a second throttling gear. The second compressor, the third heat exchanger, the second throttling gear and the second heat exchanger are sequentially in circulation connection. Or, the second compressor, the first heat exchanger, the second throttling gear and the third heat exchanger are sequentially in circulation connection. The electrical control box comprises a first control system used for controlling operation of the first heat exchange system and a second control system used for controlling operation of the second heat exchange system. The first control system and the second control system independently operate. According to the screw type unit, the standby application performance of the unit is improved; and compared with a traditional single-system unit, the occupied area of the unit is reduced, and the space structure of the unit is compact.