Abstract: : Cd_xZn_1-xS solid solution and CeO₂/Cd_xZn_1-xS heterojunction were prepared by solvothermal method, and the crystal shape, morphology, structure and elemental composition were characterized by XRD, SEM and XPS. The hydrogen production properties of Cd_xZn_1-xS solid solution and CeO₂/Cd_xZn_1-xS heterojunction were studied under visible light irradiation. The hydrogen production rate of Cd_0.3Zn_0.7S heterojunction was 3.86 mmol·g⁻¹·h⁻¹, which was 4.85 and 11.03 times that of CdS and ZnS, respectively. When the CeO₂ loading ratio was 10%, the CeO₂/Cd_0.3Zn_0.7S heterojunction had the best photocatalytic performance, and the hydrogen production rate was 7.89 mmol·g⁻¹·h⁻¹, which was 40.25 and 2.04 times of that of CeO₂ and Cd_0.3Zn_0.7S solid solutions, respectively. Under light, the electrons of CeO₂ migrate to Cd_xZn_1-xS, making the part of the heterojunction interface near CeO₂ positively charged, while the part of the heterojunction interface near Cd_xZn_1-xS negatively charged, forming an internal electric field, which enhanced the carrier separation and migration performance.