Abstract: As one of the important features of biometrics, fingerprints are widely used in criminal investigation. However, the traditional fingerprint acquisition technology is often limited to two-dimensional contact measurement, which is easy to be affected by finger humidity, force deformation and other factors, resulting in poor recognition effect. Therefore, for fingerprint measurement, this paper designs a small field of view imaging system based on structured light was. By adding lenses and other ways, the imaging field of structured light is reduced, and high-precision three-dimensional fingerprint information is obtained by non-contact measurement. At the same time, due to the influence of equipment accuracy, environmental noise and other factors, the acquired fingerprint point cloud usually contains noise. This paper analyzes the source of the acquired fingerprint point cloud noise, classifies the noise, proposes a multi-scale noise denoising method based on statistical analysis and Gaussian filter, and verifies its effectiveness through experiments.