For soft clayey foundations consolidated with the prefabricated drains method,coefficiency of consolidation,separation and depth of the prefabricated drains and the effects of well resistance and smear,etc.all directly contribute to consolidation.Taking the engineering geological condition of soft embankment test section in Zhejiang Taijin Highway for example,this paper analyzes factors affecting the consolidation results by using prefabricated drains.Coefficiency of consolidation may use Cv of indoor test to take place of Ch;at the same time,separation and depth of the prefabricated drains should not be reduced or oversized unrestrictedly in the case of the geological conditions.Instead,they should be determined rationally according to practical cases.