An effective method based on Hough transform, which is used to detect the fuzzy line fringes in image, was put forward. Taking advantages of the insensitivity feature of Hough transform to random noise and the properties of Fourier transform, the method can detect the fringes with the same period. The method can recognize the general feature of the fringes with the same period and do not recognize the single fringe. Using the proposed method, the influence of incomplete fringes to the measurement result can be efficiently avoided. In the application of the automatic interpretation of the holographic interferogram, the holographic fringes were automatically recognized and exactly counted. The experimental results show that the proposed method can avoid the influence of the uneven gray and the serious blur of fringes, and increase the test precision and efficiency of the digital holographic interferometry.