Gd₂Zr₂O₇-SrZrO₃ (GZSZ, Gd₂Zr₂O₇:SrZrO₃=7:3) composite ceramic powder was synthesized by solid state reaction. Spray drying and atmospheric plasma spray (APS) method were used to prepare corresponding spray powders and coatings, respectively. The phase compositions and microstructures of the spray dried powders and APS coatings were characterized by X-ray diffraction and scanning electron microscopy. The thermal diffusivity, thermal expansion coefficient and sintering coefficient of the coatings were characterized by a laser flash method and a high-temperature dilatometer. Both GZSZ composite powders and coatings are composed of Gd₂Zr₂O₇ and SrZrO₃. The Gd₂Zr₂O₇ powder has a pyrochlore structure, while the Gd₂Zr₂O₇ coating has a fluorite structure. And both the SrZrO₃ powders and coatings have a perovskite structure. The porosity of the coating is ~14%, and its thermal expansion coefficient after heat treatment at 1400℃ for 5 h is 9.8~11.2×10^_-6 K^_-1. The thermal conductivity of the as-sprayed GZSZ coating is ~0.8 W?m^_-1?K^_-1, which is ~20% lower than that of the SrZrO₃ coating (~1.0 W?m^_-1?K^_-1). And the thermal conductivity of the GZSZ coating increases to ~1.5 W?m^_-1?K^_-1 after heat treatment at 1400℃ for 360 h. The results showed that the GZSZ coating is a promising thermal barrier coating material.