The transmittance of photochromic glass varies with the intensity of light radiation. Hence, photochromic glass is a smart glass with energy-saving effect, which can be used to regulate the sunlight into the building. However, there are few studies on the application of photochromic glass in buildings, and there is a lack of scientific methods to evaluate its energy-saving performance. In this paper, a simplified simulation method for energy-saving performance of the as-prepared photochromic glass was established. Focusing on the energy-saving effect, different types of buildings were modeled by the energy consumption software (DeST), and the cooling and heating load and lighting energy consumption of buildings with photochromic glass were calculated and compared. The results show that, photochromic glass has an annual energy-saving ratio up to more than 10% in public buildings with large building areas and window to wall ratio above 0.6. Furthermore, in buildings with smaller building areas and window wall ratio, its main role is to block ultraviolet light and prevent glare. The results and methods of this paper can provide a reference for the research of energy-saving performance of photochromic glass, and have significance to promote the practical application of photochromic glass.