Abstract: Malignant tumors seriously endanger human life and health, and their treatment has always been a research focus of scientists all over the world. Natural flavonoids and their derivatives have a variety of biological activities, especially regarding antitumor growth, with unique biological activities. They can interfere with the growth cycle of tumor cells, change the mitochondrial membrane potential, promote apoptosis, and can reduce the immune escape of tumor cells and prevent tumor metastasis by improving human immunity. In the human body, they regulate the biological signal transduction, leading to the up-regulation of pro-apoptotic protein expression. They inhibit the growth of solid tumors by regulating the growth of vascular epithelial cells and blocking the formation of blood vessels in tumor tissue. Recent studies have shown that these compounds can play an important role in the treatment of various human tumors and are expected to be developed into new antitumor drugs. This review summarizes the recent research results on the antitumor mechanism of flavonoids and their ability to inhibit tumor growth.