You can’t drink overnight soy milk for the following reasons: 1. Overnight soy milk is easy to breed pathogenic microorganisms, and the nutrients in soy milk provide the conditions for the reproduction of pathogenic microorganisms. If you drink overnight soy milk, it is easy to lead to a high incidence of intestinal infectious diseases, causing abdominal pain, abdominal distension and harm to the body; 2, overnight soy milk after a night of placement, many of the nutrients have been decomposed and consumed, drinking such overnight soy milk can not play a role in supplementing nutrition; 3, overnight soy milk decomposition products, especially protein decomposition products are easy to cause allergic reactions, light itchy skin, heavy will cause allergic asthma and endanger the health of the body.