Objective  Due to the limited space of urban land, the mismatch between the supply and demand of urban green space and the population, and the inequity are increasingly emerging. The current quantitative research on the relationship between supply and demand of green space mainly takes urban parks as the research object, ignoring the green open space that residents use more frequently, such as mountains, forests, riverside green spaces, and greenways in cities. The balance between supply and demand of urban green open space is the key to improving residents’ sense of acquisition and happiness in daily recreational space, and is of great significance to future urban green space planning.

  Method  According to the definition and classification of urban green open space, the Gaussian two-step mobile search method was optimized, using high-precision population raster data and park POI data, taking Haidian District of Beijing as an example, from the population demand, accessibility level, the supply-demand relationship and spatial configuration of green open space in Haidian District were analyzed from the aspects of supply blind area and spatial autocorrelation.

  Result  The central urban area in the southeast of Haidian District had the largest demand, but the smallest supply; the northwest had the smallest demand, but the largest supply; in terms of accessibility, the overall area was relatively low, and 67% of the residents recreation experience level did not reach the average, and the distribution showed a polarized trend of high in the northwest and low in the southeast, with the northwest and central regions having the highest accessibility and the southeast having the lowest accessibility. There was a 23% supply blind space in the whole area. In the west and southeast, there was a serious spatial mismatch of oversupply and undersupply.

  Conclusion  (1) The accessibility of Haidian District is generally low, with a trend of high in the northwest and low in the southeast. The areas with high accessibility index are concentrated in Xiangshan Street and Wenquan Town; the low value of accessibility is concentrated in Xiangshan Street and Wenquan Town. The areas are concentrated in Qinghe Street, Xisanqi Street, Shangdi Street, and Zhongguancun Street. (2) The relationship between resource allocation and supply and demand is seriously unbalanced, and the space where supply exceeds demand is mainly concentrated in the southeast; the space where supply exceeds demand is mainly concentrated in the northwest. (3) Compared with park green space and small green space, urban forests, greenways, and riverside green spaces have a greater impact on the supply and demand relationship of urban green space. (4) In terms of the distribution of supply blind spots, according to the reasons for the formation of supply blind spots in various regions, we put forward the future optimization directions to improve the balance of supply and demand of green open space, such as exploiting potential space, utilizing vacated space, establishing convenient transportation, and utilizing social forces, so as to provide a basis for urban green space construction and the improvement of residents’ living well-being.