Green spaces and parks play an important role in the urban ecosystem and are vital in improving the urban ecology, beautifying the environment, and maintaining the physical and mental health of urban residents. Beijing has been facing various challenges, such as the rapid growth of the elderly population. Parks and green spaces, which play an important role in citizens’ daily lives, provide a place for senior residents to exercise, make friends, and communicate with others. As the threat of the pandemic is still present, too many visitors to parks and green spaces will hamper pandemic prevention efforts. In this study, data sources, including Baidu Map Huiyan and four-dimensional traffic data from Navinfo; surveying and mapping of geoinformatics spatial and statistical data; big data analysis; GIS spatial analysis and network analysis; and a normalization algorithm were used to assess the comprehensive capacity of parks and green spaces in the core area of Beijing to serve the elderly population in terms of demographic characteristics, accessibility, and the intensity of population mobility.