Abstract: A novel method was presented to optimize the matching of photoelectric imaging system by using information distortion parameters. The problem of spectral aliasing in photoelectric imaging system was analyzed. The object light intensity function was decomposed into a series of non-negative harmonic waves and the image harmonic waves were calculated. Thus, the information models of object, image and electro-optical system were built up. Moreover, the information distortions with different optical system cutoff frequencies were calculated, and the matching relationship between the optical system and the detector based on information distortion was described. Results show that, when the detector pixel width is 10 μm, the Gaussian spectrum should choose the diffraction-limited optical system with the cut-off frequency of 100 mm^-1 in order to obtain the minimum distortion 0.144 1.