Methacrylonitrile is an important fine chemical product,which is used as organic chemistry midbody to produce polymethacrylimide and methyl methacrylate.The major production technologies of methacrylonitrile,including acetone-cyanohydrins method,mixed C4 ammoxidation method,isobutylene ammoxidation method,and other novel routes were introduced.The main downstream application of methacrylonitrile was also summarized.