Abstract: The laser cleaning experiment of 38CrMoAl samples was studied by pulsed laser. The influence law of cleaning threshold, damage threshold and laser power density of surface pollution of 38CrMoAl samples was studied by microscope, white light interferometer, step profiler and infrared thermometer. The result shows that when the laser power density increases to 1.22 J/cm2, the surface contaminants begin to be effectively removed, corresponding to the cleaning threshold, when the power density increases to 3.11 J/cm2,the substrate begins to be damaged, corresponding to the damage threshold; When the energy density between the cleaning threshold and the damage threshold, the cleaning mechanism is vibration effect; When the power density equals to 2.36 J/cm2, all the contaminants on the sample are removed, the roughness is not changed after cleaning, the substrate is not damaged. Laser cleaning can satisfy the fine cleaning needs of 38CrMoAl parts.