Abstract: The automatization for the parameterization and modularized modeling and analysis of semi-ellipse surface cracks are realized through program using MSC Marc software. The modularized finite element modeling and contact techniques were adopted to simulate semi-ellipse surface cracks．Radial singular unit meshes in the crack front were use to simulate the singular stress field of the crack front. At the same time, the boundary conditions of crack model by finite element contact technique were applied to simulate the far field stress of the crack model. In addition, the crack virtual extension technique was used to calculate the J integral on the crack front. Then the stress intensity factor distribution can be transformed based on the linear elastic finite element theories. On the other side, the crack front was dispersed to realize orthogonal extension and the new crack front is fitted to get continual extension simulation.