Abstract Aiming at the problems of the Shuibuya Project's wide grading antiseepage material, the method of filter design is researched. Through the filter protective soil tests and fissure self healing tests, the filter design standard of the wide grading anti seepage materials of Shuibuya Project is given. In the filter protective soil test, the method on air dry fine grained material with horizontally throwing is proposed, which is more convenient and quick than that of Xie Nade's dense mud test. The Shuibuya Project's gradings are not only wide, but their change extends are large, almost involving various wide grading materials that can be used as antiseepage .So the particle size D50=0.5—1mm(average value 0.6mm)may be employed as the antiseepage design standard of wide grading antiseepage material.