In order to study the evolution of thermal performance of key materials for building roof insulation under multi-field coupling, based on the cold climate zone, the thermal performance evolution of rigid polyurethane foam and vacuum insulation panels was tested under the coupling of temperature, humidity and stress. It is found that in cold climates, the thermal conductivity of rigid polyurethane foams increases with the number of cycles which lead the thermal conductivity decreases, and in the presence of additional stress, multi-field coupling accelerates the aging of rigid polyurethane foams. The thermal conductivity of the vacuum insulation panel increases slowly with the number of cycles and the multi-field coupling will slightly accelerate the aging of the vacuum insulation panel. However, the additional stress has little effect on the aging of the vacuum insulation panel. The surface and cross-section microstructure of the thermal insulation material were observed by three-dimensional digital microscope and scanning electron microscope. It was found that the polyurethane cell structure changed significantly under multi-field coupling, based on this, the mechanism of thermal performance evolution was discussed.