Abstract: Determination of the gasket’s compression-springback behavior is necessary for the contact analysis of bolted flange joints. In a diesel engine cylinder head-gasket-exhaust manifold assembly, the gasket typically experiences temperatures around 500 °C, presenting huge challenges for experimental testing. A finite element model was developed to simulate the compression-springback characteristics of a multi-layer metal gasket installed in the front end of the exhaust manifold in a high-power diesel engine. Through contact dynamics analysis, the load-displacement curves were obtained at both ambient temperature and 200 °C, which were compared with the experimental results to validate the model’s accuracy. Further analysis with higher temperatures revealed significant thermo-mechanical effects: the compression displacement increased from 0.522 mm at ambient temperature to 0.762 mm at 700 °C. Concurrently, the critical load for plastic deformation on the middle gasket layer decreased substantially, resulting in pronounced widening of the hysteresis gap between compression and springback curves. The contact stresses of the front flange of the diesel engine exhaust manifold were calculated using the compression-springback curves of the gasket at room temperature and 500 °C. The minimum contact stresses of the gasket were obtained, 5.57 MPa and 6.95 MPa, respectively, with an error margin reaching 20%. These temperature-dependent behavioral changes critically influence the contact stress distribution across gasket-flange interfaces.