Abstract: For exploring the fracture property so as to provide evidence for the design and integrality assessment of graphite component in high temperature reactor pebble bed module (HTR-PM), extended finite element method with experimental verification which is based on the cohesive zone model was used to simulate the structure of graphite dovetail key-keyway. Also, sensitivity analysis of the fracture and geometric parameters was under consideration in the numerical analysis. The results show that maximum failure load of the graphite dovetail key-keyway structure is 50.7 kN, and increases with the corner radius. The maximum failure load is sensitive to the tensile strength, and becomes more sensitive with the increasing of the corner radius. The maximum failure load is less sensitive to the fracture energy as well as Young’s modulus, but turn into more sensitive with the decreasing of the corner radius. The maximum failure load is insensitive to the Poisson’s ratio. Great agreement is achieved between the simulation, literature predictions and experiments results. In addition, this paper would be practical to other types of reactors with graphite component such as molten salt reactor (MSR) and fast reactor.