<p>Subsea pipelines with egg-shaped profiles may develop cracks during extended operational periods. A cost-effective trenchless rehabilitation method involves installing a thin-walled liner adjacent to the cracked pipeline’s inner surface. This rehabilitation enables the pipeline-liner system to maintain normal liquid/gas transportation functions. The liner can be heated to decrease transportation viscosity and enhance flow rates. However, thermal instability frequently occurs when thin-walled liners are exposed to elevated temperatures. This research presents a computational scheme to analyze the thermal properties of an installed liner with an egg-shaped profile. A modified sine function describes the radial inward deflection, considering the liner’s rigid and tight encasement within the pipeline. Response formulae are derived by combining classic shell principle with the principle of minimum potential energy. These formulae are then solved to determine equilibrium curves and buckling temperature variations. A rigorous verification process validates the computational scheme, demonstrating that the calculated equilibrium curves align well with previous research findings. The study examines the effects of various thickness-to-radius ratios on the egg-shaped liner’s thermostability and compares the thermal buckling resistance between egg-shaped and circular liners. Results indicate superior thermostability in egg-shaped liners compared to circular configurations.</p>