BaSO₄是一种优异的隔热填料，但其以单一形式应用于隔热涂料中，隔热效果并不理想，因此需对 BaSO₄进行表面改性。采用溶胶-凝胶法，利用正硅酸乙酯对 BaSO₄进行表面改性制备了 BaSO4/SiO2复合粉体，并以其为隔热填料，以水性聚氨酯乳液为成膜物质，制得 BaSO₄/SiO₂隔热涂料。利用 XRD、FT-IR、SEM、EDS对粉体及涂层的结构和形貌进行表征分析，并探究正硅酸乙酯添加量对涂层的太阳光反射比、近红外反射比、半球发射率及隔热性能的影响。结果表明：随着正硅酸乙酯添加量的增加，BaSO₄/SiO₂涂层的太阳光反射比及近红外反射比逐渐增加，半球发射率先升高后降低，隔热温差先增大后减小。当正硅酸乙酯质量分数为 25%时，涂层的太阳光反射比为 81. 88%，近红外反射比为 79. 79%，半球发射率为 0. 89，此时 BaSO₄/SiO₂涂层的隔热温差为 19. 98 ℃，表明 BaSO₄/SiO₂涂层具有良好的隔热效果。

BaSO₄ is an excellent thermal insulation filler，but necessary surface modification of BaSO₄ is required for its unideal thermal insulation effect when applied in a single form. BaSO₄/SiO₂ composite powder was prepared by sol-gel method using tetraethyl orthosilicate（TEOS） as surface modifier. BaSO₄/SiO₂ thermal insulation coatings were prepared by using the prepared composite powder as thermal insulation filler and waterborne polyurethane emulsion as film forming material. The structure and morphology of the prepared composite powder and coating were characterized by XRD，FT-IR，SEM and EDS. The effects of TEOS addition on the solar reflectance，near-infrared reflectance，hemispherical emissivity and thermal insulation properties of the coating were investigated. The results showed that，with the increasing of TEOS addition，the solar reflectance and near-infrared reflectance of the coating increased gradually，the hemispherical emission and the thermal insulation temperature difference increased first and then decreased. When the mass fraction of TEOS was 25%，the solar reflectance，near-infrared reflectance，hemispherical emissivity and thermal insulation temperature difference of the coating were 81. 88%，79. 79%，0. 89 and 19. 98 ℃，respectively，showing good thermal insulation effect.