Abstract: Non-steroidal anti-inflammatory drugs (non-steroidal anti-inflammatory drugs, NSAIDS) Clinical application of nearly a hundred years, since glucocorticoids are widely used in clinical after the application of these drugs once reduced. However, corticosteroids can cause dependence, short-term can not be immediately discontinued, long-term drug use can cause many serious adverse reactions, thus NSAIDS has been renewed emphasis on research. Non-steroidal anti-inflammatory drugs have anti-inflammatory, anti-allergic and analgesic effect, and no corticosteroid side effects, and therefore its application in ophthalmology received increasing attention. With the extensive use of NSAIDS in the eye and the increasing use of such drugs, the efficacy and safety has been an ophthalmologist's attention. Nepafenac is a strong and effective non-steroidal anti-inflammatory drug (NSAID) before ammonia difloxacin drugs for the treatment of cataract surgery-related pain and inflammation. In this paper, based on thio-acetamide Synthesis Nepafenac.