Sulforaphane is a naturally occurring active substance derived from cruciferous vegetables with potent antioxidant and anticancer properties. Researches have shown that sulforaphane has good bioavailability and can be absorbed by the small intestine through passive transport, followed by excretion in the form of urine via the hydrophobic acid pathway. In addition, since sulforaphane is easy to be absorbed and metabolized, wrapping sulforaphane with nanomaterials can improve its bioavailability and stability, prolong its action time in human body, and better utilize its therapeutic effect. In terms of mechanism of action, sulforaphane can activate Nrf2 and HSF1 signaling pathways, induce the expression of phase II detoxification enzymes HO-1, NADPH, GST and HSP, thus regulating the concentration of oxidative stress ROS in vivo; inhibit NF-κB signaling pathway, thus suppressing the expression of inflammatory factors TNF-α, IL-1 and IL-6; regulate epigenetic modifications, thus inhibiting HDAC and DNMT, and increasing the concentration of histone H3 and H4. By regulating the expression levels of the above factors, sulforaphane can affect the occurrence and development of cancer, neurodegenerative diseases and other diseases. In recent years, several phase I/II clinical trials have shown that sulforaphane has good drug-generating properties. For example, researchers have found that patients with skin cancer have not shown any health problems and their corresponding functional problems have improved greatly after long-term use of sulforaphane. This suggests that in the future sulforaphane has a very high medicinal potential for the treatment of cancer and neurodegenerative diseases. In this paper, we review the pharmacokinetics, target of action and safety of sulforaphane and its research progress in tumor and neurodegenerative diseases to provide a reference for the future application of sulforaphane in the treatment of tumor and neurodegenerative diseases.