Abstract: A miniaturization design of optical system was accomplished based on the technical specifications of optical correlators. Both the Fourier-transform lens and the collimating and beam expanding system adopted the telephoto structure, which could maintain the long focal length and decrease the optical tube length. The optical path was folded with right-angle reflection prism to make the system layout more compact. The structure of the optical system was optimized with ZEMAX. The total length of the miniature optical correlator was less than 150 mm, and the system width was less than 90 mm. This improved optical system utilized double optical path processing structure, and achieved real-time recognition. The experimental results demonstrate that the recognition system has a good correlative performance, as well as the features of low noise, high detection precision.