Abstract: To study the variation law of thermal conductivity of thermal barrier coatings (TBCs) in severe service environments, like high-temperture salt spray atmosphere, etc., the Lattice Boltzmann Method (LBM) and the analysis model of heat transfer process were used to analyze the effects of the following factors on the insulation performance of the TBCs, such as the thickness of ceramic layer and bond layer, the convective heat transfer coefficient on flue gas side and cooling air side, and so on. Results show that the thermal insulation property of TBCs reduces rapidly after corrosion, which weakens with increasing effective thermal conductivity of TBCs after sintering. The thickness of ceramic layer plays a decisive role to the thermal insulation properties of TBCs, i.e. the thermal insulation properties of TBCs increase almost linearly with the thickness of ceramic layer, while the bond layer has little effect. The increase of convective heat transfer coefficient would lead to reduced temperature of blade substrate on cooling air side, but to increased temperature of blade substrate on flue gas side.