Abstract: In the volumetric radioluminescent light sources, the light originates from a volume. The light diffuses out of the luminescent body. The luminescent body, which is mixed with ZnS∶Cu and SiO₂ aerogels, is an important factor affecting the performance of volume tritium light source. In the preparation process of the luminescent body, the doping process of phosphor and the molding process of the luminescent body need to be integrated in the polycondensation process of the SiO₂ aerogel preparation process. Therefore, the appropriate gelation time is critical. The effect of phosphor ZnS∶Cu on the SiO₂ aerogel prepared by the sol-gel method was studied in this experiment. The factors influencing gelation time include the hydrolysis time, the concentration and dosage of the alkali catalyst and the reaction temperature on the gelation time. The experimental results show that the sol-gel solution can be fully hydrolyzed when the hydrolysis time is more than 24 hours. The concentration of the alkali catalyst should not be more than 0.1 mol/L to ensure the transparency of the SiO₂ aerogel. The amount of the base catalyst and the reaction temperature have obvious influence on the gelation time, and the gelation time can be controlled and adjusted by this factor. The luminescent body prepared by the developed preparation technology is measured by China Metrology Institute and the brightness value is 0.386 cd/m².