Ventilation device with oil-gas separation function

The ventilation device with the oil-gas separation function comprises a cylinder body and a filtering assembly, the cylinder body is of a hollow structure, and the filtering assembly is installed in the cylinder body; the cylinder body comprises an air inlet section and an air outlet section which are communicated with each other, an air inlet is formed in the end part of the air inlet section, the air inlet is communicated with the air outlet end of a crankcase in the air compressor, a first baffle is arranged at the top of the air outlet section, and a plurality of air outlet holes are formed in the first baffle; the filtering assembly comprises a middle shaft and a plurality of filtering plates; the top end of the middle shaft detachably protrudes out of the first baffle. The plurality of filter plates are mounted on the middle shaft at intervals, and the middle shaft sequentially penetrates through the plurality of filter plates; circulating gaps are reserved between the filter plates and the air outlet s