Abstract: A high slope belongs to the Dujiangyan to Wenchuan highway section of the national road 317, located at the right bank of Minjiang River, about 3km from Wenchuan County. The slope was local collapsed in the earthquake and threatened the road's security. The high slope deformation failure under earthquake is studied and analyzed by the physical simulation, the conclusion is that the response of slope surface is significantly larger than the ones on the bottom and internal in model, the reaction intensity is increased with the increasing of slope heights and slopes in general. Its failure type under strong seismicity is sliding, in which the massive body turns to pieces and debris, its geomechanical model is the slip\|fracturing.