In order to remove paint from aero-engine casing surface, a study on laser cleaning of Cessna 172 aircraft engine casing surface was carried out by using nanosecond pulse laser. By analyzing the surface topography and roughness of the paint removal area of the casing, the influence of laser energy density and scanning speed on the cleaning effect of the paint layer on the casing surface was explored, and the optimal process parameters of laser paint removal on the casing were determined. The surface quality, microhardness and roughness of the casing after removing paint were comprehensively evaluated. The results show that both energy density and scanning speed significantly affect the paint removal quality of casing. When the energy density is 18.33 J/cm² and the scanning speed is 1600 mm/s, the paint removal rate is 98.7%, the surface roughness S_a is 2.48 μm, the casing itself is not damaged, and the surface microhardness is increased by 1.9%, which meets the paint removal quality requirements of the casing surface. The research results provide theoretical and technical support for laser paint removal of engine casing.