Yaojia shipping hub is the last downstream hub on the middle and upper reaches of Qiantang river main stream cascade development.In view of the seepage control of seriously permeable foundation,we carry out the 3-D seepage analysis,compare the geometry size of the cutoff wall and the anti-seepage effect,optimize the anti-seepage mode,and predict the immersion,shoulder seep and leakage.The results show that the fine sand and sandy gravel lay are the main leaking path,the feature of shoulder leak is obvious,the groundwater level at both banks and leak out height on slopes are high.The longer the horizontal length of the cutoff wall,the smaller the seepage gradient at the slope foot and the less obvious the anti-seepage effect. The length of cutoff wall is recommended to be no longer than 600 m.Leakage still exists on the lower side slope under the anti-seepage measures,so,various anti-seepage measures,such as inverted filter,shall be taken to enhance the seepage stability.