Abstract: The mechanism and deformation behavior of warping composite buckling defects in a thin cold-rolled strip were studied. Based on the theory of shallow shells and Galerkin’s virtual displacement principle, the analytical model of buckling for the strip with an initial warping defect was established, the critical buckling load and critical wavelength were obtained, and the influence rules of buckling affected by a warping defect were analyzed. The results show that the critical buckling load increases with the increase of the warping value. Under C warping, the critical wavelength of center buckling increases with the increase of the warping value, but the critical wavelength of edge buckling decreases with the increase of the warping value. Under L warping and C-L composite warping, the critical wavelength of center buckling and edge buckling decrease with the increase of the warping value. The mode of warping composite-buckling defects was obtained by designing cold-rolling experiments in a test mill, which proved the correctness of the analytical model. The simulation analysis for the conditions of rolling experiments was established by using ANSYS, the model of buckling was obtained, which was in a good agreement with the experimental results, and the critical buckling conditions of this buckling model were also achieved, which further verified the analytical calculation results.