Abstract: Water, energy, and food are intricately interconnected due to mutual demands and systematic influences, potentially posing latent security risks to natural resources, socio-economic systems, and ecological environments. Therefore, analyzing the security of water-energy-food (WEF) systems from a systemic correlation perspective contributes to the sustainable utilization of resources and high-quality socio-economic development. This paper focused on the security of the WEF system in the Yangtze River Economic Belt (YREB). Firstly, the concept of field was introduced into the security analysis framework of the WEF system, elucidating the concept and connotation of WEF system security in the "resource-society-ecology" field. Twenty-seven indicators were  selected to construct an evaluation index system for system security. Secondly, based on the co-evolutionary characteristics of the WEF system, the GRA model and FCEM model were combined to assess the security level of the WEF system in the YREB from 2012 to 2022. Finally, the GM(1,1) model was employed to predict the evolution trend of WEF system security in the YREB from 2025 to 2030. The results indicated that: （1） There existed significant differences in the field security level of the YREB from 2012 to 2022, with a spatial trend of high-value areas expanding from upstream to downstream. (2) The security level of the WEF system in the YREB fluctuated between 0.65 and 0.70 from 2012 to 2022, indicating an improvement in security level. （3） The security level of the WEF system in the YREB would remain within the security range from 2025 to 2030, however a slight downward trend was predicted. These findings help identify the spatial and temporal differentiation and the evolution patterns of WEF system security in the YREB, and may provide a reference for exploring ways to enhance WEF system security in the region.