The fairness of urban park service is related to the social equity and quality of life of residents, especially the differentiation of social strata and the widening gap between rich and poor, and the residents are increasingly pursuing higher quality green open space, so reasonable park layout is very important for green space planning and construction. To this end, this paper selects Taiyuan urban park as the research object, analyzes the differences in the service capacity of the township streets and parks based on the differentiation of social spatial structure, and then selects the representative low-educated population, the elderly and children as the target group, from the macro and micro level to study whether the urban park service is fair to these vulnerable people, and identify the imbalance area of per capita park service lower than the overall level of the research area, and then put forward optimization suggestions, with a view to providing reference for future urban planning. The research shows that the service ability of the park is not equally different from the spatial difference between social status, population structure and family structure. At the macro level of the study of vulnerable groups, children are more unfair to the less educated and elderly people who enjoy urban park services. The unfairness of the township streets around the urban fringes, urban and rural staggered areas and the high-speed surrounding the city is more serious, while there is a clear oversaturation of supply in the urban center.