Abstract: In order to study on the anchor mechanism of cable more precisely，the surrounding rock dynamic stress of anchor hole under the earthquake load were studied by numerical simulation through FLAC3D software，and the effect of gradient elastic modulus，the gradient Poisson's ratio，the gradient cohesion，the gradient internal friction angle of the rock mass surrounding anchor hole on the compressive stress of mortar and the shear stress of the rock mass surrounding anchor hole under the earthquake load were investigated.The results showed that the gradient elastic modulus had a really significant effect on the shear stress of the rock mass surrounding anchor hole，and the gradient cohesion and the gradient internal friction angle also influences the compressive stress of mortar and the shear stress of the rock mass surrounding anchor hole.The results enriched the content of anchorage type pressure mechanism under the earthquake load，which can supply reference to engineering.

Key words: Pressure type cable, Seismic loads, Gradient change, Mechanical properties