The invention discloses a pumping mechanism and particularly relates to a fluid pumping mechanism. The fluid pumping mechanism comprises a fluid groove, a tee pipe, a connecting pipe, a sealing tank and a vacuum chamber. Anti-corrosion layers are sprayed on the inner wall of the fluid groove, the inner wall of the tee pipe, the inner wall of the connecting pipe, the inner wall of the sealing tank and the inner wall of the vacuum chamber respectively. The tee pipe comprises a first pipeline, a second pipeline and a third pipeline. The connecting pipe is sequentially provided with a connector matched with an opening of the sealing tank, a gravity valve and a feeding pipe. A port of the feeding pipe and a port of the first pipeline are arranged below the liquid level of the fluid groove. The vacuum chamber and the connecting pipe are connected through a vacuum supply pipe. An installation seat made of rubber is arranged at the bottom of the sealing tank. The fluid pumping mechanism overcomes the technical defect that fluid is prone to being oxidized in the prior art, and the fluid oxidization risk is lowered.