Vacuum pump is through mechanical, physical, chemical and other methods of pumping the container to be evacuated to obtain the vacuum device equipment. The working principle of the vacuum pump can be divided into two types of gas capture pump and gas pump, vacuum pump vacuum technology can be divided into mechanical and physical methods. First, the law 1, the varactor vacuum pump, pump cycle is to use the cycle of change to complete the intake and exhaust to achieve the purpose of pumping. This pump points reciprocating, rotary two. 2, momentum transfer pump, which relies on high-speed rotating blades or high-speed jet, the momentum transfer to gas or gas molecules, the gas from the pump inlet to the outlet continuously. Molecular vacuum pump steam jet pump, diffusion pump belongs to this category. Second, the physical law Gas trap vacuum pump is a gas molecule is adsorbed or condensed in the pump on the surface of the vacuum pump, the following forms: 1, adsorption pump. A trapping vacuum pump relies on the physical adsorption of adsorbents with large surface area, such as porous material. 2, getter pump. It is a vacuum pump that uses a getter to chemically trap gas. Getters are usually metals or alloys that exist in the form of lumps or deposited fresh films. 3, getter ion pump. It is to make the ionized gas through the electric field or electromagnetic field adsorption on the surface of the getter material to achieve the purpose of pumping. It has the following two forms. a, evaporative ion pump: ionized gas is absorbed in the pump in an intermittent or continuous manner sublimation (or evaporation) and coated on the suction pump material inside the wall, in order to achieve a vacuum pump. b, sputter ion pump: the pump is ionized gas adsorption in the cathode from the continuous splashing out of the gettering material to achieve the purpose of pumping a vacuum pump.