Stomach cancer is one of the common diseases among digestive tract tumors. In the late stage of stomach cancer, weight loss, indigestion and digestive bleeding will mostly occur, and vomiting black of stomach cancer is usually a manifestation of digestive bleeding, and some patients will also have black stools. Some patients may also have black stools. When stomach cancer spits out black stuff, it is often because of the black color of spit out material formed by the interaction and reaction between gastric mucous membrane erosion, ulceration, bleeding and acidic material in gastric cavity, which is mostly a manifestation of gastrointestinal bleeding. If the manifestation of gastrointestinal bleeding occurs, it is recommended to go to the emergency department or gastroenterology department of the hospital in time, because the more black things are vomited out in this kind of situation, the longer time it takes, the more likely it will aggravate the anemia, and even have the danger of life.