Vulnerability research is a new paradigm in the context of global environmental change and sustainable development. Taking vulnerability as a system's sensitivity to pressure and lack of adaptive capacity, this paper adopts territorial space as the research object and establishes a framework for assessing the vulnerability of territorial space from the viewpoint of ecological protection, agricultural production, and urban development as three major functional orientations. The framework consists of pressure, sensitivity, and adaptive capacity assessment, as well as an index of 28 indicators, thus emphasizing the application of a comprehensive integration method for vulnerability assessment. Xingyang City, Henan Province, China was chosen as the study area, and the results showed that territorial space vulnerability on the basis of ecological protection, agricultural production, and urban development in 2018 was relatively stable, the identified vulnerable space constituting only about 12%, 9%, and 10%, respectively, of the total land in the study area. By analyzing the causes of the different levels of territorial space vulnerability, corresponding strategies for mitigating pressure, reducing sensitivity, and enhancing adaptive capacity were formulated. From the perspective of local governance, these strategies provide innovative analytical and technical methods for assessing the current status quo in spatial planning and for achieving sustainable development goals. Finally, we point out that research on territorial space vulnerability needs to gradually improve the conceptual framework and assessment indicator system, focus on further research on multiple scales and typical regions, and improve the guidance resulting from vulnerability research.