Abstract: To explore the vulnerability and main impacting factors of bay ecosystem, based on the VSD model of “exposure degree, sensitivity and adaptability”, this paper quantitatively evaluated the ecosystem vulnerability of Yueqing Bay in 2010-2012, 2015-2017 and 2020-2022 using analytic hierarchy pricess (AHP) and fuzzy comprehensive evaluation methods. Results showed that Yueqing Bay was classified at the level of “moderate vulnerability” in three periods, and the comprehensive score of vulnerability decreased gradually and showed a trend of gradual improvement. The overall exposure degree changed little, the sensitivity and adaptability gradually improved in three stages. The main factors of anthropogenic stress were the ratio of industrial output value to GDP, the ratio of beach reclamation area and the density of mariculture. The main sensitive factors were biomass, biodiversity comprehensive index and water environment comprehensive index. In order to improve the health of the ecosystem in Yueqing Bay, it is necessary to optimize the industrial layout and mariculture structure, strengthen the comprehensive regulation and restoration of the coastal zone and promote the special legislation on biodiversity protection and improve the intensity of ecological supervision for more citizen participations.