Major function-oriented zoning, a key spatial planning strategy in China, aims to coordinate resource endowments, socio-economic development, and subsequent planning initiatives. However, the existing framework for major function-oriented zoning relies predominantly on socio-economic statistical indicators at the regional level, often neglecting the critical role of carrying capacity. To address this limitation, we assessed both the current state and dynamic trends of the carrying capacity to identify risk and advantageous zones for major functions, with the objective of optimizing major function-oriented zoning in the Yangtze River Delta region, China. Our findings indicate that 47 counties are experiencing significant pressure under the current carrying capacity, while 57 counties exhibit a deteriorating trend in their capacity. Over half of the counties are categorized as having an overloaded carrying capacity. Based on this analysis, 66 counties have been designated as risk zones for major functions. Consequently, the optimization of major function-oriented zoning requires adjustments in 10 counties, incorporating the identified risk and advantageous zones to enhance spatial planning efficacy. This study proposes an enhanced methodological framework for major function-oriented zoning by fully integrating carrying capacity assessments, offering substantial support for territorial spatial planning in China. We believe that these improvements contribute significantly to more resilient and sustainable regional development strategies.