Fingerprint recognition systems are widely used in the field of biometrics. Many existing fingerprint sensors acquire fingerprint images when the fingerprint of the user is brought into contact with a solid flat sensor. Because of this contact, the input images from the same finger can be very different and there are latent fingerprint problems that can lead to fakes and hygiene problems. For these reasons, a non-contact fingerprint recognition system has been investigated, in which a non-contact fingerprint image can be captured. While this system can solve problems that arise through finger contact of the user, other challenges arise, for example, low valley-valley contrast and 3D image mapping to 2D. In this article we discuss both the disadvantages and the advantages of non-contact fingerprint systems and introduce the hardware and algorithm approach to solving problems. We describe the structure of the illuminator and the wavelength of light to acquire high-contrast fingerprint images. To solve the problem of 3D 2D image mapping, we describe the method for eliminating fingerprint images from strong sight difference. Experiments show that the non-contact fingerprint system performs better than the conventional touch-based system.