A two-stage screw compressor and an air conditioning system. The two-stage screw compressor includes: a housing with an intake port and an exhaust port provided thereon; a low-pressure stage screw set axially arranged in the housing and connected to the intake port; a high-pressure stage screw set axially arranged in the housing and connected to the exhaust port; a drive motor axially arranged in the housing; and a transmission gear set for simultaneously transmitting a torque provided by the drive motor to the low-pressure stage screw set and the high-pressure stage screw set; wherein, the drive motor, the low-pressure stage screw set and the high-pressure stage screw set are axially arranged on the same side of the transmission gear set.