Abstract: Based on field test of pre-stressed anchor cables in deep excavations,The standard value of the ultimate bond strength in anchorage section is analyzed and calculated through measured data.It is higher than the current standard in certain loess layer when the anchor cable length is set properly.From the different load displacement curves of the test anchor cables,the pre-stressed anchor cables in loess layers and other viscous layers are basically consistent in the service conditions and load transfer,the working state of the anchor cable is reflected clearly in the curves of the test under the tension load of each stage,and the relevant fitting formula is obtained through experimental data and curves.In the end,the rigidity of the anchor cables is reverse calculated with the test data and is compared with the current standard,some beneficial results are obtained.The results can provide references for the design and construction of deep excavations in loess layers.