Green spaces in cities provide an urban landscape where human beings can live close to nature. The inclusion of green space is an important part of improving the living environment of residents and an effective way to improve their physical and mental health. Taking the main urban area of Hangzhou as the research subject, a remote sensing image of urban green space was interpreted by GIS technology to obtain the green space layout of the main urban area of the city. At the same time, the population density was used as the resistance factor, the number and area of green space within 500m network distance of traffic network as classification standard. Secondly, perceptual data from 665 residents were obtained through questionnaire surveys of 45 high, medium, and low residential areas with different grades. Finally, a structural equation model was used to evaluate the inter-group analysis based on the number of green spaces and playtime, and distinguish the differences between various groups and the causes of these differences. The model was also used to assess the number of green spaces and the area they covered, residents' cognition, motivation, and green space attraction, plus the relationship between health benefits and satisfaction. The results show that the number of urban green spaces and the number of times the residents use the spaces have a significant positive relationship with the residents' well-being. The residents' perceptions of the role of green space and their motives for visiting green space further affect their physical and mental health. Indeed, an understanding of the importance of urban green space will stimulate residents' enthusiasm for using green spaces and increase the frequency with which they visit them. In addition, individuals with different social attributes have different needs for green space; therefore, the resulting welfare effects and level of satisfaction will also vary. Finally, suggestions are made for the future development planning of urban green space from three aspects: increasing the number of street green spaces and neighborhood parks around residential areas, enhancing the attractiveness of green spaces, and raising the awareness of residents of the role of urban green space.