The flaw propagation angle is a vital factor in the behavioral study of fractures, especially in the case of structures under dynamic or fatigue loading. In this paper, Eddy's current testing has been used with the finite element modeling method to determine the flaw angle for a two-dimensional axisymmetric problem in a gas tube. Moreover, the influence of the flaw angle on the sensor impedance during the scanning process is carried out. On the other hand, the inverse problem is optimized using one of the most recent and effective metaheuristic optimization algorithms called Grey Wolf Optimizer (GWO).It allows for defining an optimized relationship between the flaw angle and the sensorimpedance. Simulations are carried out to validate the proposed approach and show its efficiency in accurately determining the flaw angle.