In order to achieve stable luminescence quantum efficiency from cesium lead halide perovskite nanocrystals embedded glasses, this work investigated the effects of water quenching and secondary low-temperature thermal treatment on the structure and optical properties of CsPbBr₃ nanocrystals embedded glasses. Results show that water quenching of high-temperature heat-treated glass can restrain the growth of CsPbBr₃ nanocrystals, and significantly reduce the photoluminescence quantum efficiency. Then, low-temperature thermal treatment can promote the growth, improve the quality of CsPbBr₃ nanocrystals, and enhance their photoluminescence quantum efficiency. The research results have certain reference value for the preparation of cesium lead halide perovskite nanocrystals embedded glasses with stable photoluminescence quantum efficiency and the development of optoelectronic functional devices.