Abstract: In order to meet the requirements for online real-time detection of complex surface quality of parts based on machine vision, based on the double telecentric imaging principle and aberration theory, a double telecentric optical system with wide field of view and large depth of field was designed by using ZEMAX optical design software. The system consisted of six lenses, with working wavelength of the visible range, system magnification of -0.061, working distance greater than 390mm and the maximum field of view of 180mm. The results show that the maximum distortion of optical system is less than 0.1%, the range of depth of field reaches to 80mm, the modulation transfer function in the whole field of 100lp/mm is greater than 0.4 and the maximum of telecentric is controlled within 0.012°. Various aberrations are corrected very well and the image quality is good. The design of structure meets overall design requirements of double telecentric system.