A new type of self expansion and high strength preloading anchorage technology was presented with large amount of expansion anchor solids as anchor solids. Test device and method for high strength pre compression anchorage system that can eliminate CT artifacts, obtain maximum expansion stress(>35MPa), and accurately locate and scan were developed. Combined with the analysis technology of the quantitative CT image of the ring layer, a prediction formula for CT value was established with the content of expansion agent and the distance of overlying surface as variables. To compare expansive soil anchor solid and anchoring in vitro, let CT value, diameter, ring to the expansion stress and strain be the main representation, CT value was get along with the changing regularity of linear expansion, expansion force size, ring to the spatial evolution rule, body strain increases with the increasing layers of change rule. Layers of soil anchor in vitro from internal to external layers of compactness linearly reduced. Mechanism of linear increase of large diameter anchor solid was elucidated. The results reveals the contribution of the increase of density and normal stress induced by auto expansion to the anti uplift effect of pulling force in the high strength preloaded anchorage system.