The invention discloses the application of a nereistoxin compound in prevention of marine biofouling, and relates to the nereistoxin compound. The nereistoxin compound can significantly inhibit the attachment of a marine biofouling organism namely barnacles and inhibit shellfishes from generating byssi, has an efficient antifouling activity, and has low toxicity to a non-target organism namely fairy shrimps at the same time. The nereistoxin compound is obtained through biomimetic synthesis of natural organic compounds, is easy to degrade, is environment-friendly, and is high in safety; moreover, a synthetic process of the nereistoxin compound is mature, so that the nereistoxin compound is suitable for large-scale production, and has a great potential for scale application to marine antifouling paints.