Abstract: In this paper, the influence of laser etching on the preparation of diamond film was studied, the influence of laser etching on diamond film was studied, the morphology and structure of the substrate and carbon film were detected by scanning electron microscope, Raman spectrum and X-ray experiment, and finally the field emission properties of carbon film were studied by using the field emission secondary structure. The effects of laser etching on the preparation and field emission properties of diamond films are simply analyzed.