Air compressor is introduced under the screw type air machine working process: through the inlet air filter will filter dust or impurities from the atmosphere by the intake valve after entering the compressor host, in the process of compression and injection cooling lube oil blending, after the compression of mixed gas from the compression chamber into the oil and gas separation tank, to get a high temperature and high pressure oil and gas, respectively. Due to machine working temperature, the high temperature and high pressure oil and gas must be sent to the respective cooling system, in which compressed air after cooler, finally to use the system; And the high temperature and high pressure lubricating oil after cooler, return to the oil into the next round of cycle.