The utility model discloses a sealing tank having a gas-liquid separating effect and belongs to the field of petrochemical equipment. The sealing tank structurally comprises an air lifting pipe, a tank body and an exhaust pipe. A bubble cap is arranged in the tank body and is cylindrical, the top of the bubble cap is sealed, the bottom of the bubble cap is open and is downward vertically, the top end of the air lifting pipe penetrates the tank body to be welded to an inner wall of the top of the bubble cap, and the side of the upper portion of the air lifting pipe is provided with at least one air outlet. The top of the tank body is provided with a top cover, the a top cover is provided with the exhaust pipe, the exhaust pipe is communicated with a tank body inner cavity, the top of the bubble cap is provided with a plurality of gas-liquid separating baffles, and an inner wall of the top cover is provided with a plurality of gas-liquid separating baffles. The sealing tank has the advantages of being reasonable in design, simple in structure, easy to process and low in cost; a breather valve, a positive pressure preventing tank and a negative pressure preventing tank used on an existing storage tank can be replaced, the volatilization and volatilization concentration of poisonous and harmful substances in the tank are effectively reduced, the gas-liquid separating effect is achieved, and the running cost is low.