Postoperative drainage fluid from abdominal drainage tube after gastric cancer surgery may be postoperative bruise blood or pus formed by infection. 1. Post-operative bruise: clinically, most gastric cancers are operated by traditional open abdominal surgery with relatively large traumatic surface, because there will be bleeding after operation, which needs to be drained through drainage tube, and the drainage fluid is mostly bright red or dark red blood with small bleeding volume; if the amount of drainage fluid per hour is >200ml, there may be active bleeding, which needs to be treated by caesarean section to find the bleeding point to stop the bleeding. 2. Pus: some patients’ postoperative anti-infection or inadequate wound care cause infection problem will form pus, and the drainage fluid will be turbid and yellow, etc. It is necessary to use antibiotics such as cefixime tablets and amoxicillin to carry out anti-infection treatment in time, and to promote inflammation until the drainage fluid disappears. It takes a period of time to recover from gastric cancer after surgery, and it is necessary to do a good job in anti-infection and later consolidation treatment.