Abstract: Soils and water emerge as important natural resources for plant growth and development. Understanding the responses of vegetation to water and soil characteristics is crucial to the scientific management of agricultural production. However, there is a lack of studies on the quantification of coupling characteristics of these factors. To reveal the coupling characteristics and responses among water, soils, and vegetation, this study investigated the farming areas in Huachuan, Jixian, and Youyi counties in the hinterland of the Sanjiang Plain. Using a survey of vegetation and the analysis of soil and water samples, this study established an index system for the assessment of the water-soil-vegetation coupling. The weights of the assessment indices were determined using principal component analysis, and a water-soil-vegetation coupling coordination model was constructed for the farming areas. Additionally, the primary factors influencing plant growth were analyzed using gray correlation analysis. Results indicate that vegetation, water, and soils in the farming areas are strongly coupled. Primary factors influencing vegetation growth and development include soil bulk density; sand content; zinc, boron, and copper contents, and the calcium ion concentration and hardness of water bodies. Notably, the coupling coordination degree is not consistent with the coupling degree. Specifically, water, soils, and vegetation in the farming areas exhibit strong coupling, characterized mainly by sound coordination. In contrast, some areas of Huachuan and Jixian counties exhibit poor coupling among water, soils, and vegetation. This is primarily due to water pollution, soil texture, and deficiencies in trace elements. Therefore, it is necessary to improve the groundwater ecosystem and implement protective farming of cultivated land. The coupling model of water, soil and vegetation established in this paper provides and important basis for ecological environment protection and restoration.