As the complexity of integrated energy systems increases, so does the demand for component coupling, leading to heightened system uncertainties. Hence, establishing an evaluation index system and assessment model for the flexibility of integrated energy is a crucial prerequisite for enhancing the flexibility of these systems. Initially, this paper constructs evaluation systems for integrated energy system flexibility resources at both the system-wide and localized levels. Then, integrating economic, environmental, and safety factors, this paper employs the analytic hierarchy process, the entropy method, and fuzzy evaluation to develop a comprehensive evaluation model. This model is used for radar chart analysis of index weights and fuzzy comprehensive evaluations based on scenarios implementing eight different flexibility resource scheduling schemes. Results indicates that among the set of flexibility resource scheduling schemes, the highest flexibility score is achieved by the scheme combining gas internal combustion and gas boilers. However, when considering multiple factors such as economic viability, environmental impact, and safety, the two scheduling schemes, gas internal combustion engine combined with heat pump and water energy storage, and gas internal combustion engine combined with heat pump and energy storage station, are more prominent.