In order to study the lateral seepage characteristics of the New Xiagang double-lane ship lock chamber under the condition of a non-homogeneous layered ground and several piles,two-dimensional seepage model with ABAQUS finite element software is built.The seepage stability during the period of running and maintenance is checked,and reasonable scheme for seepage-proofing and depressurization is raised.The results show that seepage equipotential lines refract at the junction in the soil which relates to the relative ratio of permeability coefficient.The laminar flow is obvious at the silty sand layer behind the sidewall.In the most dangerous condition of maintenance,soil flow destruction occurs on the outlet section in lock chamber.Impervious walls are only set behind the sidewall and the intermediate lock wall,the lock chamber is in the critical state of soil flow destruction.Adding the vertical tube for depressurization on the outlet section,the seepage stability can be improved efficiently.The flow direction along the side pile may change because the head along the pile may increase progressively after decrease progressively.Local detour flow occurs in the intermediate lock wall,and hydrostatic section account for most.A great water level difference occurs after setting impervious walls.