The purpose of this study is to explore the adaptability of the retractable roof of stadium buildings to the external climate, and then to explore the energy-saving effects of the retractable roof on stadium buildings. This study takes the Jiading Gymnasiums of Tongji University in Shanghai as an example, and it uses digital simulation technology to apply AIRPAK CFD multiphysics simulation software to perform digital simulation analysis of the two operating conditions of Jiading Gymnasium. Using the somatosensory temperature and the Predicted Mean Vote (PMV) as control indicators, the indoor environment of the two working conditions was analyzed. The experimental results show that retractable roof can effectively improve the indoor environment. It is concluded that the retractable roof of the stadium can effectively adjust the indoor environment of the building by opening and closing, improve the comfort of the indoor thermal environment, and reduce the energy consumption of the stadium.