The integration of Geographic Information Systems (GIS) into sustainability studies is crucial for advanced urban planning and ecological management. This study explores the distribution and accessibility of urban green spaces as critical ecological services, particularly in the context of post-pandemic recovery and urban resilience. Utilizing a comprehensive spatial database, this research involves the extraction of Point of Interest (POI) data specific to green spaces within Yangzhou, a representative city in the Yangtze River Delta, China. The analysis employs the two-step floating catchment area (2SFCA) method to quantitatively assess green space accessibility for local residents. Our findings reveal pronounced disparities in green space accessibility between urban and peri-urban zones, highlighting substantial environmental inequity. These disparities suggest a need for targeted urban planning interventions. By employing a multi-modal evaluation framework, this study not only underscores the variations in urban green space accessibility but also proposes GIS-based strategies for enhancing spatial planning at both micro and macro urban scales. The outcomes serve as a foundational tool for policymakers to devise more equitable distributions of ecological services, thereby fostering sustainable urban ecosystems and enhancing the quality of life for all city dwellers.