Vomiting black-brown liquid in advanced stage of cancer may be caused by gastrointestinal bleeding, first of all, we should do vomit examination to clarify whether it is gastrointestinal bleeding or not, if it is bleeding, we need to take active treatment to stop bleeding. Vomiting black-brown liquid in advanced stage of cancer may be caused by bleeding phenomenon due to infiltration of blood vessels by cancer tissues and detachment of necrotic tissues, and vomiting black-brown liquid may also occur in gastrointestinal bleeding, first of all, it is necessary to take measures of hemostasis, which can be done through endoscopic hemostasis or hemostasis by drugs such as growth inhibiting hormone, octreotide and so on. After stopping bleeding, patients with anemia can be treated by transfusion of hemoglobin. Patients with advanced cancer can be treated with palliative care to improve their survival period and quality of life, such as radiotherapy. It is suggested that family members should do a good job in caring as well as nursing, and go to the hospital for treatment as early as possible.