Abstract: The red bed is a clastic sedimentary rock mainly deposit by red continental sedimentation, the rock property is mainly composed by sandstone, mudstone, siltstone and arenaceous shale.It is alternate for the soft rock and hard rock, in existence by alternating layers, the layer combines weak.had influenced by the regional structure,the layer has great torsion , fold and high angle fault. The mud stone in the red bed has the character of weak water permeability, stick up to airslake is weak,has obvious differential airslake and the speed of disaggregation is quickly. the red beds slope influenced by the interaction between rock with water will lead wedge instability,slope creep deformation and disintegration ect.