To study the time-dependent creep effect of siliceous slate and the deformation and failure evolution law of high slope，in this paper，the shear creep test of indoor rock mass was carried out to plot the shear creep duration curves of siliceous slate under different normal stresses，the shear displacement-time curve，and the creep rate-time curve under different normal loads and shear loads.The average creep rate and shear load variation of siliceous slate were studied，and the long-term shear strength parameters of siliceous slate were determined by the steady-state creep rate method.The results show that in the creep test，the sensitivity of cohesion is significantly greater than that of internal friction angle.Finally，the high slope of ZK 33 + 450 siliceous slate on the Shiyan-Wuxi Expressway is used.Based on the Mohr-Coulomb model，the finite difference method was used to analyze the deformation and failure mechanism of the high slope of the typical siliceous slate under shear creep conditions.