Methotrexate is a folic acid antitumor drug, the finished product is an orange-colored crystalline powder, which mainly plays the role of inhibiting the growth and reproduction of tumor cells by inhibiting dihydrofolate reductase, preventing the normal conversion of dihydrofolate into tetrahydrofolate and blocking the synthesis of DNA and RNA. Methotrexate is mainly used in the treatment of various types of acute leukemia, especially acute lymphoblastic leukemia, malignant lymphoma, non-Hodgkin’s lymphoma and mycosis fungoides, multiple myelopathy, head and neck cancer, lung cancer, various soft tissue sarcomas, breast cancer, ovarian cancer, cervical cancer, as well as malignant staphyloma, choriocarcinoma, testicular cancer and psoriasis. Common adverse reactions of methotrexate include sore throat, nausea, vomiting, abdominal pain, gastrointestinal bleeding, and loss of appetite; at high doses, hematuria, proteinuria, oliguria, azotemia, and even uremia can occur.