Improved mobile phase holding device

The invention relates to an improved mobile phase holding device. The device comprises a wide-mouth bottle for holding a mobile phase, a liquid inlet pipe having a detachable joint, a bent pipe having a valve, and a plastic bag having an air inlet and an air outlet, wherein the wide-mouth bottle comprises a glass bottle body, and a bottle plug matched with the glass bottle body; the bottle plug has two through holes respectively matched with the liquid inlet pipe and the bent pipe; one end, extending into the wide-mouth bottle, of the liquid inlet pipe is fixedly connected with a glass sand core filter; the valve of the bent pipe is fixedly connected with the air inlet of the plastic bag; the volume of the plastic bag is one half of the volume of the wide-mouth bottle; and the inner wall of the bottom of the wide-mouth bottle takes the shape of a recessed hemisphere. The improved mobile phase holding device has the advantages of simple structure, convenience, practicability and lower production cost, and is suitable for promotion and application.