Rapid urbanization and climate change have intensified environmental challenges, heightening health risks-especially in densely populated, polluted cities. This study develops a composite pollution health risk assessment model based on the “Hazard - Exposure - Vulnerability” framework, employing Xi’an as a case study to analyze the spatiotemporal evolution and dominant factors of health risks from 2015 to 2022. The results indicate periodic fluctuations in health risks, with declines yet persistent volatility within the old city, and increasing risks in expanding regions such as Weiyang and Yanta due to population concentration and urban development. Risks are distributed spatially in a “center-high, periphery-low” pattern, with the old city constituting high-risk zones, while ecological buffers like Huyi and Lintong demonstrate lower risks. The study affirms key risk drivers and recommends area-specific strategies across five dimensions-spatial structure, functional layout, ecological environment, infrastructure, and social resources-to enhance urban resilience and improve the effectiveness of health risk mitigation.