Abstract: The local opening area destroys the overall geometric continuity of the structure, leading to stress concentration and trigger the initiation and propagation of fatigue cracks. In order to solve the problem of crack propagation and fatigue life prediction in the opening corner area, a new three-dimensional model of small-scale called opening corner specimen was established with reference to the opening structure in actual engineering. The FRANC 3D was used to simulate the dynamic crack growth progress of the specimen and the influencing factors during crack propagation in the numerical calculation were discussed. Finally, the relationship curve between the crack length, the number of load cycles and the stress intensity factor were obtained. The results show that the power exponent n=2, the long and shallow initial shape of the crack could withstand more fatigue load cycles. The power exponent has little influence on the calculation of stress intensity factor on the crack propagation path, but the initial shape of the crack has influence on it. The shape of the crack front gradually changes from ellipse to circle in the process of crack propagation, and the crack front line finally approximates to a straight line. There are differences in the results of dynamic and quasi static methods to calculate the crack propagation parameters. In the rapid growth stage, the mode Ⅰ single crack during stable growth stage gradually transforms into mixed mode crack until fracture failure.