Abstract: on August 31, 2014, Yunyang Foreign Languages School in Chongqing encountered a once-in-a-century torrential rainstorm which gave rise to obvious slide evidences of the slide mass. The aim is to evaluate the stability of the slide mass in consideration of the effect of hydrodynamic pressure after the rainstorm infiltration, the theoretical basis is the saturated-unsaturated seepage theory.this paper uses SEEP and SLOPE of software Geo-Studio to analyze. Further more, it analyzes the displacement and seepage characteristics under heavy rainfall condition comprehensively. The main results as follows: Firstly, the failure form and mechanism of the single landslide caused by heavy rainfall are interpreted; secondly, the evolvement rules of the displacement and seepage fields are obtained by analyzing the change characteristics during the whole failure process, it is able to provide theoretical basics for regulation project.