Under the dual backdrop of the Healthy China strategy and the concept of sustainable development, optimizing the spatial layout of primary healthcare facilities is important for fairly distributing healthcare resources and strengthening the resilience of the public health system in a sustainable way. This study introduces an innovative 3D spatial resilience evaluation framework, covering transmission (service accessibility), diversity (facility type matching), and stability (supply demand balance). Unlike traditional accessibility studies, the concept of “resilience” here highlights a system’s ability to adapt to sudden public health events through spatial reorganization, contrasting sharply with vulnerable systems that lack resilience. Method-wise, the study uses an improved Gaussian two-step floating catchment area method (Ga2SFCA) to measure spatial accessibility, applies a geographically weighted regression model (GWR) to analyze spatial heterogeneity factors, combines network analysis tools to assess service coverage efficiency, and uses spatial overlay analysis to identify areas with supply demand imbalances. Harbin is located in northeastern China and is the capital of Heilongjiang Province. Since Harbin is a typical central city in the northeast region, with a large population and clear regional differences, it was chosen as the case study. The case study in Harbin’s main urban area shows clear spatial differences in medical accessibility. Daoli, Nangang, and Xiangfang form a highly accessible cluster, while Songbei and Daowai show clear service gaps. The GWR model reveals that population density and facility density are key factors driving differences in service accessibility. LISA cluster analysis identifies two typical hot spots with supply demand imbalances: northern Xiangfang and southern Songbei. Finally, based on these findings, recommendations are made to increase appropriate-level medical facilities, offering useful insights for fine-tuning the spatial layout of basic healthcare facilities in similar large cities.

The development of primary healthcare facilities facilitates a balanced distribution of medical resources, relieving pressure on large hospitals by enhancing these facilities, thus optimizing resource allocation. Such equitable distribution not only improves the accessibility and fairness of healthcare services, but also supports their sustainable growth. This study introduces a spatial resilience framework that evaluates transmission, diversity, and stability from a spatial resilience perspective. Focusing on Harbin's main urban area's primary healthcare facilities, methods such as Gaussian-Based Two-Step Floating Catchment Area (2SFCA), network analysis-based service radius, walking impedance, and overlap analysis are utilized for spatial distribution analysis. Findings indicate significant variance in facility transmission, with Daoli, Nangang, and Xiangfang Districts showing higher accessibility, Songbei and Daowai Districts exhibiting lower transmission. The road network capacity decreases from the urban center towards the periphery in a diminishing pattern. Local Indicators of Spatial Association (LISA) identifies areas with demand-supply mismatches, primarily in northern Xiangfang District and southern Songbei District, while overall spatial connection remains balanced. Based on these findings, we propose strategic enhancements for medical facilities of corresponding levels, offering insights for similar large cities seeking to refine their primary healthcare spatial layout.