In order to obtain the change law of surface morphology of aluminum alloy after laser cleaning,a laser with pulse width of 150 ps was used to clean the oxide film on the surface of aluminum alloy. The surface morphology,micros-tructure,composition and roughness of the laser-cleaned aluminum alloy were observed and tested by optical microscope,scanning electron microscope,energy spectrometer and roughness meter. It is found that after laser cleaning,the oxygen content and roughness of the surface of aluminum alloy decrease,and the oil and oxide film are washed off, forming regular cleaning traces,which are composed of tidal tissues and tiny particles. When the energy density is greater than 1.53 J/cm,2,the surface temperature of the aluminum alloy is high,and the generated plasma gas impacts the surface of the micro-melted aluminum alloy,making the trace deeper and increasing the area and time of contact between oxygen in the air and high-temperature aluminum alloy,thus resulting in a more severe oxidation phenomenon, so that the laser cleaning traces and secondary oxidation phenomenon of the aluminum alloy surface increase when the energy density increases.