Aiming at the common cliffy lumpy?perilous rocks`s characteristics of Karakorum Highway,experimental research was carried out on the destruction of cliffy perilous rocks under the action of earthquake by refitting the original vibration table.The research focused?on lumpiness,height,joint angle and external vibration strength of the cliffy perilous rocks and the conclusion is as follows:The bigger the joint angle, the more unstable the rock body is,the 90° special vertical joint angle is extrenmely unstable,the collapse always happen above 1/3 height,almost no collapse under it,the change of joint angle from 90° to 70° brings the change of collapse model from group collapse to group sliding collapse,which is more like rock slope sliding and rolling failure.