In the practical application of Moire tomography, the intelligent recognition of effective Moire fringe areas is a crucial step. To address the cumbersome and inaccurate process of manually determining effective areas, a method for intelligent recognition of effective Moire fringe areas was proposed. First, the Moire fringes were preprocessed using a combination of the Otsu algorithm and mathematical morphology. Then, the difference values of light intensity images of straight and curved fringes with and without the measured flow field were obtained. Finally, the coordinates of the effective areas were determined based on Gaussian fitting. To verify the feasibility and universality of this method, it was applied to practically effective areas recognition of Moire fringes with different flow field structures, contrasts and fringe widths, and the automatic and accurate extraction of effective Moire fringe areas was successfully achieved. In summary, this method significantly simplifies the algorithm structure, achieving precise and reliable recognition of effective Moire fringe areas with lower computational costs.