the invention discloses a new strepsesquitriol a , a preparation method thereof and an application thereof . strepsesquitriol a , a structure as shown in formula , is a compound having a new skeleton and strongly inhibiting the formation of lps - induced tnfα but showing no cytotoxic activity , so it can be used for the preparation of anti - inflammatory drug or act as a precursor of anti - inflammatory drugs , for the treatment of multiple inflammations . therefore , the invention provides a new candidate compound for the development of anti - inflammatory drugs , and is of great significance for developing chinese marine drug resources .