<p>Based on the three-dimensional elasticity theory, the isogeometric analysis method was employed to investigate the thermal buckling behavior of composite laminated plates with irregular delaminations. The shape of the delamination was generated by rational cubic Bézier curves. By altering the control points and weights, delaminations of various shapes could be represented. Based on isogeometric analysis, three-dimensional non-uniform rational B-splines basis functions were used to describe the displacement field of the laminated plate. The eigenvalue equation of the laminated plate was derived using the principle of minimum potential energy. A multi-patch modeling approach was adopted to construct the delamination model, and the strong coupling method was used to connect the delaminated region and the intact region. This paper also considered the contact effect between the upper and lower interfaces of the delamination. The augmented Lagrangian method was employed to address the penetration problem between the upper and lower interfaces at the delamination during buckling. The results of this paper were compared with existing research results to verify the validity of the proposed method. Through a parametric study, the influence of the control points and weights of the delamination shape on the critical buckling temperature and buckling mode of the delaminated laminated plate was analyzed in detail.</p>