Abstract: YFeO₃ powder synthesized by the conventional solid-state reaction method was used as the functional pigment,and a waterborne acrylic emulsion was used as the binder to prepare YFeO₃ aqueous slurries with different dispersants. Solar heat-reflective coatings were fabricated by optimizing the slurry composition. The effects of dispersant type and solid content on the dispersion stability,rheological behavior,and thixotropic properties of the YFeO₃ slurries,as well as the near-infrared reflective properties of the coatings,were investigated. The results show that single-phase orthorhombic YFeO₃ powder can be obtained at 1 300 ℃ by the conventional solid-state reaction method,and the as-prepared powder exhibits good near-infrared reflectance,with a maximum reflectance of 97.72%. The YFeO₃ aqueous slurry shows an obvious shear-thinning behavior.With increasing solid content,the viscosity and shear stress of the slurry increase,and the thixotropic property is improved.The near-infrared solar reflectance of the YFeO₃ coating prepared from the slurry with a solid content of 70% reaches 46.64%.These results indicate that YFeO₃ can be used as a near-infrared reflective pigment for solar heat-reflective thermal-insulation coatings.