Abstract: Based on the laboratory dynamic liquefaction tests, the triaxial shear tests are carried out on the liquefied samples, and the liquefaction fluidity of loess is studied by using the fluid mechanics method.The results show that the apparent viscosity of liquefied samples increases first and then decreases when subjected to triaxial shear, that is, the flow characteristics will change from "shear thickening" to "shear thinning" .This phenomenon may be related to the special structure of loess and the conservative liquefaction standard adopted in the tests.The special geological environment and the "shear thinning" property of loess in Shibeiyuan area lead to the occurrence of low-angle and long-distance liquefaction slip disasters.