Abstract: Taking ω-type SKL15 spring clip in Vossloh300-1 rail fastening system as research object, the rail fastening system model was established by finite element software, and the mechanical behaviors of the spring clip were simulated under the conditions of three material properties (linear elastic model, bilinear model and elastic-plastic model obtained by tensile tests) and two contact properties (binding constraint and nonlinear contact). The validity of the models was verified by fatigue tests, and the influence of the material properties of the clip and the contact properties between the spring clip and embedded block on the nonlinear mechanical behavior of the spring clip was studied. The results show that when the contact relationship between the spring clip and the embedded block was nonlinear and the constitutive model of the spring clip was elastic-plastic model, the maximum principal strain direction and the maximum principal strain at the heel of the spring clip obtained by finite element simulation were consistent with the test results; the relative errors of them were 5% and 3.4%, respectively, which verified the validity of the finite element model. The mechanical behaviors of the spring clip obtained by defining spring clip material with nonlinear contact and the elastic-plastic constitutive model were close to the actual condition.