Traditional optical single finger fingerprint scanner has some problems, such as small scanning window, limited extracting feature point, serious trapezoidal distortion of fingerprint original image, which directly affect the accuracy of fingerprint identification. To acquire a fingerprint scanner system with high resolution and high identification accuracy, in this paper, the dual finger fingerprint scanner with object-telecentric optical system is designed, which enlarges the size of scanning window and corrects the angle of the trapezoidal distortion. An object-telecentric optical system model is established by Zemax optical design software. By adjusting the suitable merit function and balancing all kinds of aberration, high imaging quality is acquired. The size of effective scanning window is 40.64 mm × 38.10 m. The modulation transfer function values of the center and edge view field of image are all bigger than 0.4 with corresponding characteristic frequency at 167 lp/mm, the optical distortion is less than 1%, and the system resolution is up to 500 dpi.