There is shallow and strong permeable stratum in dike foundation, which can form a prior seepage channel, and fluid head potential isn't weakened by this channel, it is easy to cause dike foundation piping failure, and the study of failure mechanism of dike foundation piping is not clear, it still needs further study. Sand tank test is used to simulate embankment foundation influent in this paper, water block stage is drived up in test, and observing the phenomenon of fine particle loss in sand, and the key parameters of seepage discharge, seepage gradient, piezometric tube head, grain composition of sand, cone resistance and settlement are analysed. The test results show that sand on the shallow and strong permeable stratum occur piping failure when water block stage increases to 48 cm. Piping failure is divided into steady seepage stage, internal erosion of fine particles stage, internal erosion of relative fine particles stage and piping failure expansion stage. The internal erosion of fine particles in process of piping failure, and cone resistance has reduced, sand has settled, and settlement heavily focus on internal erosion of relative fine particles stage. The porosity and permeability coefficient of sand, seepage discharge and seepage gradient increase when fine particle loss. This reseach results can offer theory reference for similar projects.