Abstract： This paper introduces Professor ZHANG Zhidi's clinical experience in the diagnosis and treatment of gastric cancer. Professor ZHANG Zhidi holds that the core pathogenesis of the occurrence and development of gastric cancer is deficiency of healthy qi and exuberance of pathogenic factors， as well as deficiency in origin and excess in superficiality. She puts forward the treatment principle of focusing on protecting the spleen and stomach，fortifying the foundation and consolidating the original qi，and nurturing the healthy qi，supplemented by clearing heat and removing toxins，resolving phlegm and removing stasis，and dissipating masses to treat cancer. Combining with clinical practice and closely following the disease characteristics of gastric cancer patients in the three stages of post-operation，radiotherapy and chemotherapy，and terminal stage，she advocates staged treatment. After gastric cancer surgery，equal emphasis is placed on reinforcing healthy qi and attacking toxins，with the latter aiming to clear residual cancer toxins. During the radiotherapy and chemotherapy stage， reinforcing healthy qi is the main approach while attacking toxins is auxiliary， and the latter focuses on clearing drug toxins. In the terminal stage，great importance is attached to protecting the vitality of the spleen and stomach； for attacking toxins， the strategy of defending as attacking and replenishing before attacking， replenishing after repeated attacks is adopted. Meanwhile， attention should also be paid to psychological counseling for patients and regular disease education in clinical practice，thus achieving definite clinical effect.