Abstract: The finite element software ABAQUS was used to establish K-eccentrically braced steel frame models with six kinds of support node angles, and the hysteretic characteristics of K-eccentrically braced steel frame structure were simulated and analyzed. Based on the skeleton curve and hysteretic curve of the model obtained from the simulation analysis, the eigenvalues of each loading stage were fitted, the regression equation of the skeleton curve model and the stiffness degradation law were obtained, and the restoring force model of K-eccentrically braced steel frame structure was established. The skeleton curves of restoring force model and the finite element calculation results were compared to verify the correctness of the restoring force model. The results show that the restoring force model is in good agreement with the finite element analysis results. The established restoring force model can provide a reference for the elastic-plastic change and seismic analysis of K-eccentrically braced steel frame structure.