The invention relates to a 5/7/6 taxane diterpenoid compound shown in a general formula (I), which is obtained by constructing a six-membered exocyclic unsaturated ketone unit on a C cycle of a 5/7/6 taxane diterpenoid framework. The invention relates to an anti-tumor drug composite, wherein the anti-tumor drug composite comprises the compound shown in the general formula (I) of patent claim 1 with effective treatment dose and an acceptable carrier in pharmacy. The invention also relates to a synthetic method for the 5/7/6 taxane diterpenoid compound shown in the general formula (I), as well as the application thereof for preparing anti-tumor drug.