A miniaturization design of optical system is accomplished according to the technical specification of an optical recognition system.Fourier transform lens and collimating & expanding system both adopt the telephoto structure,which decreases the optical tube length to a great extant while satisfies the precondition of long focal length.In order to shorten the system length,a binary optical element is introduced.The optical system structure is optimized with computer-aided design software ZEMAX.The beam path is folded effectively so that the structure of the system is more compact.The total length of the miniature optical recognition system is 130mm,and the width is 90mm.The experimental results demonstrate that the recognition system has a good correlative performance,and also has the virtues of low noise and high precision.