Preoperative diagnosis of malignant tumor and postoperative pathological diagnosis of gastric adenocarcinoma can be treated by surgery, chemotherapy, radiotherapy, targeted therapy and other methods, so patients do not need to be overly panicked. Gastric adenocarcinoma is a common malignant tumor of digestive system, which can be caused by Helicobacter pylori infection, heredity and other factors. After diagnosis, according to different stages, the main treatment for patients with surgery opportunity is surgical resection, after which radiotherapy and chemotherapy can be supplemented according to the condition, and for patients without surgery opportunity, radiotherapy, radiotherapy or chemotherapy can be used. Chemotherapy utilizes blood circulation to make chemotherapeutic drugs reach the lesions. Commonly used chemotherapeutic drugs for gastric cancer include oxaliplatin, 5-fluorouracil, paclitaxel and so on. Radiotherapy uses the energy released by high-energy rays to kill tumor cells. It is often combined with chemotherapy and other common treatment. Targeted therapy is a more precise therapy for mutated targets, which has the advantage of fewer side effects. Commonly used drugs include trastuzumab. All the above drugs and treatments should be applied under the guidance of doctors.