What we usually call chemotherapy actually refers to the treatment of tumors with chemical drugs. More than 50 kinds of chemical drugs have been used for the treatment of malignant tumors, and more than 10 kinds of cancers have succeeded through the application of chemotherapy. The cure rate (5-year survival rate) is 10% to 90%. Such as choriocapillary epithelial carcinoma, acute lymphoblastic leukemia, testicular tumor, etc.; there are more than 10 kinds of cancers that can achieve significant efficacy after chemotherapy, with an efficiency rate of 10% to 90%, such as skin cancer, prostate cancer, breast cancer, etc. The advantages of chemotherapy in comprehensive treatment are mainly: 1. to reduce the scope of surgery; 2. to reduce intraoperative tumor cell spreading and the incidence of recurrence and metastasis after surgery; 3. to prolong survival time. Of course, the effect of chemotherapy is still far from satisfactory, and its shortcomings include: 1) insufficient selectivity to tumor cells; 2) most chemotherapy drugs have obvious toxic and side effects; 3) inhibitory effect on the body’s immune mechanism; 4) cancer cells cannot be killed 100% of the time.