Based on ancient medical writings and modern medical knowledge, this paper summarizes and analyzes the anatomical features, physiological significance and pathological changes of “screen gate” of seven important portals. It is considered that screen gate belongs to the small intestine and is one of the five orifices of stomach. It is closely related to the spleen and stomach. It shows the function of timely open and close, and helps the small intestine to separate clear and excrete turbid, which plays an important role in the digestion and absorption of food and drink and the excretion of dregs. There may be pathological changes such as fu organs failing to transport and clear, heat obstructing intestines, disorder of clear and turbid, and the treatment on pathological changes is aimed at restoring the function of screen gate.