Abstract: The coprecipitation method enables atomic-level homogeneous mixing of metal ions, effectively mitigating powder composition segregation and enhancing doping uniformity. In this study, non-doped IZO nanopowders with an In:Zn atomic ratio of 1:1 synthesized via coprecipitation was first selected as the research subject to investigate the effects of final precipitation pH and calcination temperature on phase composition and morphology, thereby establishing optimal process parameters. Subsequently, rare-earth-doped PrIZO, NdIZO, and TbIZO nanopowders were prepared with a Pr/Nd/Tb:In:Zn atomic ratio of 0.01:1:1. TG-DSC was adopted to analyze the thermal decomposition, phase transformation and crystallization behavior of different precursors. Phase structure and composition ratios of both precursors and calcined powders were characterized by XRD, while SEM and TEM were utilized to examine micro-morphology and particle size distribution, while EDS and FT-IR verified elemental composition and distribution. The results demonstrate that rare earth doping effectively modulates the thermal behavior, crystallization and microstructure of IZO powders. Uniform, well-dispersed and high-sphericity doped IZO nanopowders were successfully fabricated, and the influencing mechanism of different rare earth elements on the structural and microscopic properties of IZO precursors and calcined powders was clarified.