Laser engraving device with image preprocessing is described in this paper. A pattern is imported into a computer by a scanner, then the image information is processed. According to the size required and using the density of 84 dpi, a desired picture is engraved by an axial flowing CO2 laser beam. The objects engraved can be wood, glass, china, marble, stainless steel, etc. The maximum engraving area is 1000*1500 mm2.