Abstract: Dump stability during rainfall period is taken as research object，combined with accumulation characteristics and meteorological conditions of a dump of Tangshan，based on the different algorithms of multiple modules，such as SLOPE/W，SEEP/W of Geo-studio software，the soil water characteristic curve and permeability coefficient function are estimatedThe minimum safe stability coefficient of the mine dump slope in the natural state is calculatedVariation characteristics of Seepage and stability of the dump slope in different rainfall condition are analyzedThe results show that within certain rainfall intensity，immersed surface decreases gradually with the increase of rainfall duration，and pore water pressure is increasingThe coefficient of safety stability is gradually reducedThe slope gradually turns into instabilityThe increase of rainfall intensity will increase reduction rate of slope stability coefficient，with the increase of rainfall intensity and duration，the slope will eventually evolve into an unstable state

Key words: Dump slope, Stability, Rainfall intensity, Rainfall duration