In order to analyze the seismic safety of an upstream tailings dam, the equivalent viscoelastic theory, Seed liquefaction theory and Newmark sliding deformation theory are used to calculate and analyze the ground motion displacement, acceleration, liquefaction area, seismic stability of dam slope and seismic permanent deformation of the tailings dam. The calculated results show that under the action of Ⅶ degree earthquake, which is the dam’s designed resistant level, the distribution rules of dynamic displacement and acceleration are reasonable. The horizontal and vertical dynamic displacement extremum was 6.39 cm and 0.72 cm, respectively, and the horizontal and vertical dynamic acceleration extremum was 4.06 m/s2 and 2.64 m/s2, respectively. The liquefaction zone occurred in the surface of the beach which was inundated by tailwater and did not affect the whole dam body. The minimum safety factor of the dam slope was 1.09 under the action of the earthquake, and the cumulative permanent deformation was 11.95 cm after the earthquake. In general, the seismic safety performance of the dam is good, except for a small liquefaction area in the shallow dam body far away from the dam slope.