Abstract: Slope failure is a major type of geological hazard induced by earthquake.Combining with the engineering project,a numerical simulation model of soil slope is established with the FLAC3D program.The paper examines and compares the plastic zone,horizontal displacement and the fracture surface of slope whether supported with bolts or not under static state, and the axial force of bolts,the plastic zone,horizontal displacement and plastic state of slope whether supported with bolts or not under stability of the slope with and without bolts at different time under static state and earthquake.It distinguishes the stability of slopes and discusses the failure mechanism of slopes.It is shown that,the bolts for slope have very good supporting role.Bolts in supporting role plays the role mainly by pulling force, and along with the increase of elevation and the decreases of axial force.Slope with or without bolts under earthquake can be damaged in different ways.Research results can be the reference frame for the design of slopes supported with bolts under earthquake.