CeO2-ZrO2 solid solution is widely used in automotive three-way catalysts. In this work, Ce0.35Zr0.55La0.05Pr0.05O2 solid solutions were prepared by a co-precipitation method. The effects of precursor moisture calcination on the properties of cerium zirconium solid solution and catalytic behavior of Pd supported catalysts were investigated systematically. The results show that the moisture (content of 66.58 wt%) in precursor promotes the crystal grain growth of the cerium zirconium solid solution, enriches the pore channels, and enhances the dispersion of cerium zirconium particles, leading to high thermal stability. After thermal treatment at 1000 °C for 4 h, the aged surface area reaches 48.32 m2 g−1 (a 14.86% increase compared with the common sample). The oxygen storage capacity is also improved by the precursor moisture calcination, with high oxygen storage capacity of 599.08 μmolO2.g−1. The precursor moisture calcination obviously broadens the air/fuel ratio window and improves the catalytic performance of the aged palladium supported catalyst.