The invention provides a dinardokanshone A (DNK-A) compound and its preparation method and application. The compound is (2'R, 4aR,4'aR,5S,8'S,8'aS)-1-hydroxy-4a,4',5,8'a-tetramethyl-8'-(propane-1-ene-2-yl)-1',2',4a,4'a,5,5',6,6',7,7',8,8'a-dodecahydro-[2,2'-bisnaphthalene]-3(4H)- ketone, is obtained by separation and purification of rhizome of Nardostachys chinensis Batal., has strong activity of serotonin transporter, and can be applied in preparation of medicines for treating diseases such as depression, anxiety disorder, schizophrenia, obsessive-compulsive disorder, neurodegeneration and the like.