Rotary vane vacuum pump is mainly composed of pump body (stator) and rotor. More than two rotating blades are installed in rotor slots, and some pumps have springs between them. The rotor is eccentrically installed in the pump cavity, and the gap between its outer edge and the top surface of the pump cavity is 2 ~ 3 microns. When the rotor rotates, under the action of centrifugal force, the rotating blades slide back and forth along the groove and always keep in contact with the inner wall of the pump cavity, dividing the pump cavity into two or more variable volume working chambers. When the rotor rotates clockwise, the volume of the suction cavity communicating with the suction port gradually increases from zero, the gas pressure in the cavity decreases, and the pumped gas is continuously sucked from the suction port. At the same time, the volume of the exhaust cavity communicating with the exhaust port changes from large to small, and the gas in the suction cavity is compressed. When the gas pressure is higher than the atmospheric pressure, the exhaust valve is pushed open to exhaust the atmosphere. When the rotor rotates continuously, the pump continuously sucks air.