Emulsification and carbonization of vacuum pump oil and blockage or damage of vacuum pump oil filter are two reasons that affect vacuum degree of vacuum pump. If it is not frequently replaced and manually maintained during long-term use, the oil of pronotek vacuum pump will be emulsified or carbonized, which will lead to a series of problems such as wear of vacuum pump cylinder, blockage of oil pipe and blockage of oil filter. When the oil mist separator is blocked, the gas pumped into the pump body will not be easily discharged. At this time, the pressure in the pump body is too high, the pumping speed decreases and the vacuum degree decreases.