Indazoles are a class of organic heterocyclic compounds, also known as 1,2-diazaindene and benzopyrazole. Indazole is a good bioisomer of phenol, which is more lipophilic than phenol and less prone to phase I and II metabolism. Indazole derivatives have a wide range of biological activities, and it has been confirmed that indazole compounds have anti-tumor, analgesic, anti-inflammatory and other drug activities. Anticancer is the most important application field of indazole drugs. Renal cell carcinoma, solid tumor, nausea and vomiting caused by chemotherapy and leukemia are the main indications of this structural backbone drug.