［Objective］ To address the operational challenges faced by PMMA cover plates in polar marine environments，including low-temperature intrusion and floating ice collision in polar marine environment.［Methods］A dual-layer composite coating system was developed，consisting ofan epoxy-based thermal insulation primer with low thermal conductivity and high adhesion，and a polysiloxane-based topcoat with high wear resistance and impact protection.［Results］The topcoat exhibited a wear value of 64. 5 mg at -35 ℃ under 500 g/1 000 r. Meanwhile，the coating system maintained surface integrity after undergoing -30 ℃ ice impact testing while demonstrating excellentsalt spray resistance and weather resistance. Additionally，this system reduced the thermal conductivity of PMMA covers from 0. 141 W/（m·K） to 0.108W/（m·K）， while the thermal conductivity of the primer was as low as 0. 049 W/（m·K）. In a -55 ℃ low-temperature environment，coated and uncoated PMMA samples were used as insulation box covers. After sealing at room temperature and resting for60 minutes，the internal temperature difference between them reached 10. 61 ℃，meeting equipment service requirements.［Conclusion］ This coating system simultaneously achieves effective thermal insulation，low-temperature wear resistance，resistance to floating ice impact，and excellent weather resistance in an energy-neutral manner. It provides a viable solution for high-reliability protection ofpolar equipment in environments characterized by the coupled effects of low temperatures，high salinity， and floating ice.