Abstract: The silicon carbide coating layer of the coated fuel particles was regarded as the bearing shell in the model. Considering the statistical distribution of the geometric parameters of coated layers into the pressure vessel failure model, the effects of the statistical variations of geometric parameters on the failure fraction were studied with the method of the Monte Carlo simulation. The results indicated that the failure fraction of the coated fuel particles was related to the particle geometric parameters such as kernel radius, thickness of porous layer, thickness of the inner pyrocarbon layer and thickness of silicon carbide, and kernel radius and thickness of porous layer were the main effect factors.