Abstract:In order to study the stability response of the slope under earthquake conditions，based on the strength reduction method，the static analysis and dynamic and time history analysis of the slope were carried out with the three-dimensional finite element model，the characteristics of slope instability and safety factor slope stability were compared under different working conditions. The results show that when the soft rock slope of the reservoir with the height of 98.6 m is excavated and supported by shotcrete， system anchor bolt and local prestressed anchor cable，affected by seismic condition，the overall displacement and characteristic section displacement of the slope increase significantly，and the maximum displacement increases by 7.6 times；The plastic zone depth of the slope increases obviously，and the maximum depth of the plastic zone increases by 1.5 times；The change of principal stress value of slope is small，and all of them are in compression state；Under static and dynamic conditions， the slop is generally stable，and the slope safety factor is reduced by about 25%；The safety factor of the finite element strength reduction method corresponding to the static and dynamic working conditions meets the specification requirements.