Brucea javanica (BJ), a key representative of traditional Chinese herbal medicine, is derived from the dried mature fruit of Brucea javanica (L.) Merr., a plant in the Simaroubaceae family. Its pharmacological activity is largely attributed to diverse chemical constituents. To date, approximately 200 distinct chemical constituents have been isolated and identified, mainly comprising quassinoids, triterpenes, alkaloids, steroids, phenylpropanoids, and flavonoids. Contemporary pharmacological studies have demonstrated the significant activities of BJ in various areas, including anti-tumor, anti-inflammatory, and anti-parasitic effects. Notably, its oil form (Brucea javanica oil) has been extensively utilized in treating various cancer types. This review aims to systematically summarize the antitumor components, mechanisms of action, and clinical applications in cancer therapy, with the goal of providing theoretical support for further antitumor research and the development of new BJ-based drugs, highlighting its potential as an antitumor agent.