Methotrexate is an anti-tumor drug, clinically used in all types of acute leukemia, especially acute lymphoblastic leukemia, malignant lymphoma, multiple myeloma, etc. It can also be used to treat head and neck cancer, lung cancer, various soft tissue sarcomas, psoriasis, breast cancer, ovarian cancer, cervical cancer, as well as choriocapillaris epithelial cancer, testicular cancer and other tumor diseases, its side effects are manifested in the following aspects: 1. gastrointestinal reactions The side effects are as follows: 1) Gastrointestinal reactions, including lip ulcers, pharyngitis, nausea, vomiting, abdominal pain, diarrhea, etc.; 2) Liver abnormalities, which may lead to hepatocyte necrosis, fatty liver and liver fibrosis when taken orally for a long period of time; 3) Cough, shortness of breath, pneumonia or pulmonary fibrosis when used for a long period of time; 4) Bone marrow suppression, which is mainly manifested as white blood cell and platelet reduction. 3, the suppression of bone marrow is mainly manifested by the reduction of white blood cells and platelets, long-term oral administration of small doses can obviously lead to bone marrow suppression; 4, there may also be hair loss, skin redness, itching or rash, and low white blood cells may be complicated by infection.