After the dust or impurities in the atmosphere are filtered out by the air inlet filter, the air enters the compressor host through the air inlet control valve. During the compression process, the air is mixed with the injected cooling lubricating oil. The compressed mixed gas is discharged into the oil gas separation tank from the compression chamber. At this time, the oil gas discharged from the compression is separated by collision, interception, and gravity, and most of the oil medium is separated, and then enters the oil gas fine separator for secondary separation, The compressed air with little oil content is obtained. When the air is compressed to the specified pressure value, the minimum pressure valve is opened, the compressed air is discharged to the cooler for cooling, and finally sent to the use system.