The improved Fourier transform phase measurement method for measuring the quality parameters of an image intensifier is proposed. Two frames of orthogonal sinusoidal gratings—one with the fringe direction at and the other one orthogonally at —are designed to serve as the projected gratings. While the gratings are projected onto the input port of the measured image intensifier by the spatial light modulator one-by-one, the corresponding deformed patterns on the output port of the measured image intensifier are captured with the CCD camera. The fundamental frequency components of the captured patterns are obtained after Fourier transform and filtering, and the phase caused by the distortion of the measured image intensifier is retrieved successfully by phase unwrapping. The multiple quality parameters of the image intensifier can be obtained by phase-to-distortion matching at the same time effectively. The simulated and experimental results display that the method is feasible and applicable in measuring the quality parameters of image intensifier.