Abstract: Local or overall initial geometric defects may inevitably occur in the manufacturing, laying and operation of submarine pipelines. To study the transverse buckling behavior of pipelines with defects laid on the seabed surface, the nonlinear numerical model for transverse thermal buckling of pipelines with 5 kinds of initial geometric defects was established firstly, and then the accuracy of the finite element model was verified. The influence of defect types and nonstraightness on the transverse buckling behavior of pipelines was emphatically analyzed. The results show that the transverse buckling deformation poses a great threat to the safe operation of submarine pipelines. The greater the nonstraightness, the smaller the critical temperature rise will be, and the more prone the pipelines will be to the transverse thermal buckling. Under the condition of the same nonstraightness, the smaller the absolute value of curvature at the center of the initial geometric defect of the pipeline, the stronger the transverse thermal buckling resistance will be. Finally, based on the dimensionless analysis method, the general expression was proposed for calculating the critical temperature rise of submarine pipelines with various common initial geometric defects, and it is anticipated to provide a reference for the thermal buckling design of submarine pipelines.