The invention relates to a method for separating and extracting C15H18O5 from Cichorium glandulosum Boiss.et Hout and use of C15H18O5 the English name of which is 11B, 13-Dihydrolacurin. The method is characterized by comprising the following steps: soaking the root of Cichorium glandulosum Boiss.et Hout by ethanol; collecting the percolate by a percolation method; obtaining a thick extract by a reduced pressure distillation device; passing the extract through a silicagel column, an octadecylsilyl column and a Sephadex LH-20 column; eluting; and drying the eluant by the reduced pressure distillation device to obtain dry powder which is the monomer C15H18O5, the English name of which is 11B, 13-Dihydrolacurin. The compound has the effect of preventing anti-hepatic fibrosis, namely, the compound inhibits activating and proliferating effect of hepatic stellate cells, so that the C15H18O5 with the English name of 11B, 13-Dihydrolacurin can be used as a lead compound for preventing anti-hepatic fibrosis.