In recent years, Point of Interest (POI) in electronic navigation maps has been paid increasing attention in urban geography and urban ecological research. The urban green space is very important to the production and residential facilities of its inhabitants. Whether the allocation system of urban green space is scientific or not has an important impact on the supply and demand of urban ecosystem services. Therefore, to plan urban green space rationally, it is very important to explore the association between urban green space and living and work space. Furthermore, with the rapid development of cities, citizens' living quality is better and their demand for urban green space is higher. However, urban green space always decreases under the pressure of urban expansion. The conflict between the increasing need for green space and the decreasing amount of it has impeded the development of cities. As the capital of China, Beijing is a huge city with twenty million people and rapid expansion; the situation of its urban green space, especially the relationship between urban green space and citizens, is typical in China. This study focused on the situation of urban green space in Beijing area. By using the POI data from the electronic navigation map within the fifth ring road of Beijing urban area, the study simulated the thermodynamic map of the spatial distribution of urban residents' workplaces and residential areas. In addition, the thermal characteristics of the green spaces in different radius service areas were analyzed. The results showed that inside the Beijing fifth ring road, the coverage of green spaces with radii of 500 m, 750 m, and 1000 m, respectively, accounted for 77.99%, 91.55%, and 97.46% of the total study area, which indicated that the spatial distribution pattern is relatively uniform from the perspective of service supply. However, in the 500 m service radius of the green space, only 51.19% of the areas in the very high-density area, 54.78% in the high-density area, and 66.21% in the medium-density area of the POI heatmap were covered, which indicated that the green space distribution was obviously not balanced from the view of service demand. Furthermore, according to the research, the urban green space was insufficient in the main commercial areas and the crowded area, and it is necessary to alleviate the mismatch between the supply and demand of green space by increasing the concentration of green space or reducing the concentration of POI. The study also showed that POI has a huge application value in urban research. The kernel density of POI could characterize the spatial distribution of the concentrated area of residents' production and life in urban areas. As this kind of data has been used in large quantities in the navigation map, it is highly accurate and should be widely used.