The utility model discloses a vacuum gas-liquid separator. Separating tank, wherein the interior of the separation tank is divided into an upper cavity and a lower cavity by a partition plate; an upper cavity movable cover plate is arranged at the upper cavity liquid outlet; a lower cavity liquid outlet is formed in the bottom of the lower cavity; the lower cavity liquid outlet is provided with alower cavity movable cover plate, the upper cavity movable cover plate and the lower cavity movable cover plate are made of rubber materials, the top of the upper cavity movable cover plate is connected with the upper cavity liquid outlet through a first lug plate, and the top of the lower cavity movable cover plate is connected with the lower cavity liquid outlet through a second lug plate. The rubber is used as the material of the upper cavity movable cover plate and the lower cavity movable cover plate, so that the sealing performance of the cover plates and the liquid outlet is improved, the gas leakage of the gas-liquid separator is effectively prevented, and the influence on the filtering of the belt filter is avoided; the upper cavity movable cover plate and the lower cavity movablecover plate are composed of nylon wires and rubber, bolts fixed to the lug plates are not prone to loosening, the problems of falling off and shifting do not exist, and therefore continuous and stable production is guaranteed.