La₂Ce₂O₇ is a fluorite-structured ceramic material with lower thermal conductivity and better high-temperature phase stability than 8YSZ, thus, it is considered as a new thermal barrier coating ceramic material. The solution precursor plasma spraying (SPPS) method is a novel coating preparation method for preparing nanostructured ceramic thermal barrier coatings in recent years. The prepared SPPS coatings have an inter pass boundary (IPB) structure, with low thermal conductivity and long lifetime. In this paper, the decomposition processes of the La₂Ce₂O₇ coating precursor were studied, and the La₂Ce₂O₇ coating was prepared by SPPS method. The nitrate solution with a molar concentration of 3.08 mol/L was used as the precursor solution, and its viscosity and surface tension were 7.17 mPa.s and 76.9 mN/m, respectively. The decomposition process of the La₂Ce₂O₇ dried precursor was characterized by STA-FTIR-QMS. The decomposition temperature and decomposition process of the precursor were evaluated, and the preheating temperature of substrate was determined to be 450 °C. The optimized spary parameters were the atomization pressure of 1.2 bar, the current of 700 A, and the liquid feed rate of 17 ml/min, determined by the Taguchi experiments. The La₂Ce₂O₇ coating prepared by using the optimzed spray parameter had a thickness of 121.59 μm after 20 times spraying, relative density of 92.4%, and hardness of 2.1 GPa. The prepared coatings were characterized by SEM, XRD, EDS and laser flash method. The results showed that the La₂Ce₂O₇ thermal barrier coating with low thermal conductivity, uniform element distribution and fluorite structure is obtained.