High-performance coatings are critical for marine engine bearing reliability. Existing research has remained primarily experimental and lacks a unified model that integrates coatings and multi-layer structures with tribological, dynamics, and thermal phenomena. Multi-factor coupling pose significant challenges to numerical stability and computational efficiency. This work establishes an integrated tribo-dynamics-thermal model for marine engine bearing systems comprising coating, alloy, steel back, and bearing cap. The model is validated against engine tests with predictions of the bushing back temperature matching wirelessly measured values within 2 °C. This validated model is used to evaluate the effects of Physical Vapor Deposition (PVD) and electroplating (ELE) coatings on dynamics, deformation, lubrication, temperature, and wear. Two improvement mechanisms are identified: contact pressure redistribution and thermal management enhancement. ELE coating reduces contact pressure by 78.35% compared to 26.81% for PVD coating. PVD coating lowers operating temperature by approximately 3 °C compared to 1 °C for ELE coating.