Aimed at the loess of Yangling Rougu,the paper used the SDT-20 dynamic triaxial apparatus to research the dynamic strength variation by change moisture content,dry density and consolidation confining pressure of original and reconstituted samples,at the same time contrasted dynamic strength differences between original and reconstituted loess,so as to provide a basis for anti-seismic design in western China. The results show that, with the increase of dry density, moisture content is reduced and the confining pressure of consolidation increases, the same destruction vibration time of the soil sample, dynamic strength increases, the difference of dynamic strength value between original soil samples and reconstituted ones increases with the confining pressure of consolidation enhances and slightly reduce with the increase of moisture content.