Abstract: Under the mode of public transportation, the accessibility and allocation equity of comprehensive parks are important indicators for evaluating urban park green space allocation and residents’ rights to enjoy public service facilities. Taking Nanjing as an example, this research builds a composite network of public transportation and, based on time-cost distance, analyzes the regional service level of comprehensive parks and their accessibility relative to the position of transportation stations. Additionally, the research adopts the Gini coefficient to judge the distribution equity and contribution of comprehensive parks respectively from the global perspective and the perspective of 15-minute living circle. The research also establishes new park site sampling points to analyze the spatial distribution of Gini coefficient changes upon addition of new park sites. The results show that the equity of park distribution can be quantitatively analyzed with accessibility as the premise and Gini coefficient as a measurement indicator; the impact of newly planned parks on the distribution equity of comprehensive parks can be clarified and the optimal site selection area can be determined through the spatial distribution of Gini coefficient updates and changes. The research can provide a quantitative area coverage reference for urban new comprehensive park planning, to improve the layout, accessibility and distribution equity of urban parks.