Abstract: The paper takes the public green space in the main urban area of Hangzhou as the research area. Around 3 essential characteristics of public green space service, convenient transportation and social conditions, on the basis of quantitative calculation, the paper discusses the accessibility of urban residents to the public green space, and introduces the verification and analysis of Baidu thermal data. The objective fairness of the public green space in the city is revealed. The results show that there is an unfair phenomenon in the enjoyment of urban public green space resources, and the urban residents mainly enjoy the green space in the core area of the city, but not enough for the high-quality large patch green space in the suburbs. The main factors that affect residents' enjoyment of public green space are as follows: the perfection of supporting service facilities, the agglomeration state of green space, residential density, traffic convenience, land use and so on, while the basic factors such as the area of green space itself have relatively little influence. The construction of rapid transportation system, the improvement of infrastructure, the increase of large patches of public green space, and the improvement of green space gathering degree are the effective ways to improve the fairness of public green space.