Aiming at the problems of slow processing speed and serious environmental pollution in hand washing and processing technology, an automatic laser washing technology combined with NC technology and laser machining was designed. A kind of method based on digital integral（DDA） method and square interpolation algorithm was designed, ensuring better accuracy under the condition of reducing redundant interpolation trajectory, improving the interpolation arithmetic speed and machining efficiency, reducing frequent startstop of motor, ensuring stability and effectiveness of the system.The dynamic simulation system of curved image was developed in VB60 programming software.The image graph was processed by laser processing on the surface of jeans, the disadvantages of washing water technology was solved, machining efficiency was improved, so batch production could be realized. The realization of laser water processing technology provides reference for design and manufacture of laser washing water.