Abstract: Ceramic fuel particles in the dispersion fuel core can form fission pores under irradiation, and the local tensile stress exceeds the material strength limit due to the interaction between pores in the fuel particles and the increase of pore pressure, which leads to the cracking of fuel particles. In this paper, the heterogeneity of pore size and position in high burnup fuel particles was considered, and the parametric modeling of microstructures inside fuel particles was realized. The influence of pore size, constrained compressive stress of matrix, temperature and pore distribution patterns on the maximum tensile stress in particle were calculated and analyzed by using the finite element method, and the distribution of potential cracking zones in particle was studied. The results show that the maximum tensile stress of ceramic fuel particle increases with the increase of pore size and temperature and decreases with the increase of constrained compressive stress. The fracture strength of fuel phase decreases, the area of potential cracking zones increases. The crack initiates from multiple sites within the fuel particle, and the origin cracking point is more possibility located at the outer space. This work provides an analytical method and numerical reference for the failure study and optimal design of dispersion fuel.