As an important natural resource and environmental element, urban green space has a profound impact on residents’ health. However, in the process of rapid urbanization, the urban green space is constantly being squeezed, and the natural environment is facing great challenges. With the continuous growth of residents' demand for green space, it is of great significance to study the impact of green space on residents' health. In this paper, the urban green space data were matched with the data of the Chinese household panel survey, and the sequential response model and moderating effect model were constructed for regression analysis. On this basis, the impact of urban green space on residents' health is quantitatively discussed, and the health inequality caused by the moderating effect of socioeconomic status is investigated, and the green space input index is further introduced as a breakthrough to explore the equity of green space. The results showed that: (1) Baseline regression found that urban green space had a significant positive correlation with residents’ health (β=0.0151, P<0.01),and the sub-regional analysis found that the health promotion effect of green space in the eastern region was much higher than that in the central and western regions; (2) Moderating effect analysis found that in the relationship between green space and residents’ health, socioeconomic factors status had a positive moderating effect (β=0.0215, P<0.01), accounting for 42% of the moderating effect,which significantly strengthened the positive impact of green space on residents, and this may also lead to the problem of unequal health benefits among residents with different socioeconomic status; (3) Heterogeneity analysis found that there were differences in urban green space and the residents’ health benefits among different income and social status groups. Groups with disadvantaged socioeconomic status benefited less from the impact of green space on health,which has caused the unfair environmental welfare of green space in China and further aggravated the health inequality；(4) Greening investment analysis found that the increasing the investment of funds and resources for environmental greening could effectively promote the health of residents. However, there were differences in the health effects of different greening investment on different socioeconomic groups. Only high greening investment could effectively improve the health benefits of green space for economically disadvantaged groups. Increasing investment in greening could effectively bridge the health gap caused by socioeconomic status. Therefore, it is recommended that the government should strengthen investment in greening, provide more social and environmental welfare guarantees for economically disadvantaged groups, and make green spaces “co-constructed and shared” to achieve the grand vision of “universal health.”