【Objective】To address the urgent need for people-centered optimization of park green spaces in high-density urban areas under the stock-based development paradigm, this study evaluates the supply-demand dynamics of urban parks in Nanjing and proposes targeted renewal strategies for community life circle units exhibiting mismatches. The research aims to identify specific locations where park provision fails to meet actual activity demand, thereby providing a scientific basis for refined park renewal.【Method】The study focusing on 2 717 community life circle units in Nanjing.An integrated analytical framework was developed. On the demand side, high-precision, multi-source heterogeneous big data were synthesized to construct a comprehensive measure of spatial vitality, capturing large-scale dynamic population demand from a human-scale perspective. This approach addresses the limitations of conventional methods reliant on static residential population data. On the supply side, the multidimensional characteristics of park provision were quantitatively evaluated using the Critic weighting method. By coupling dynamic demand measurement with multidimensional supply assessment, units characterized by “provision lagging behind demand” were precisely identified, and the spatial patterns of mismatch were revealed.【Result】The results indicate that approximately 20% of community life circle units suffer from park undersupply relative to dynamic activity demand. Fine-grained assessment revealed marked intra-urban disparities: compared with newly developed districts, older urban cores (e.g., Gulou and Xuanwu Districts) exhibit significantly higher levels of park deficiency. Park distribution displayed strong spatial heterogeneity, intensifying the mismatch at the neighborhood scale. This issue is particularly acute within the 5-minute walkable life circle, where residents’ immediate demand for convenient park access remains largely unmet.【Conclusion】Based on these findings, prioritized renewal strategies are proposed for severely undersupplied units. Rather than advocating incremental land expansion, this study emphasizes the refined optimization of existing park resources under high-density, land-constrained conditions. By integrating dynamic demand analysis with multidimensional supply assessment, this research offers a distinctive, compact, and human-centered perspective for aligning park provision with actual resident needs, contributing methodological support and practical guidance for equitable and efficient green-space planning.