Dynamic interference measuring method based on random fast axis azimuth delay array

The invention discloses a dynamic interference measuring method based on a random fast axis azimuth delay array. The method comprises the steps of adopting the delay array as the phase shift device of a dynamic interference system, wherein the delay array comprises four sub wave plates of a lambda/4 plate, a lambda/2 plate, a 3 lambda/4 plate and a lambda plate, and a polarization film of which the polarized direction forms an included angle of 45 degrees together with the horizontal direction is arranged behind the delay array; placing a standard plane mirror in a test arm of a dynamic interferometer, and collecting four linear carrier frequency phase-shift interference images by a CCD (charge coupled device); performing Fourier transformation on each linear carrier frequency phase-shift interference image and calibrating the azimuth of each sub wave plate fast axis; placing a piece to be tested in the test arm of the dynamic interferometer, and adjusting the inclined pitch and the axial defocus of the piece to be tested to obtain a synchronous phase-shift interference image; processing to obtain the phase distribution of the piece to be tested according to the calibrated fast axis azimuth of each sub wave plate and the synchronous phase-shift interference image. The method is fast and simple and is suitable for the dynamic interferometer adopting the light dividing scheme.