Abstract: The study on the variation of wetting front line and stability safety factor of embankment slope is the main judgment basis of dam flood prevention,which focuses on the safety of dam under sudden rise and high water level operation in flood season. Takes binary mixed dyke as the research object,this paper uses finite element method to analyze the seepage behavior of dyke under the condition that the water level changes obviously in flood season,and then analyzes the treatment measures when the slope drop value of the backwater slope covering soil layer and the foundation permeable soil layer is greater than the allowable failure ratio drop.