In this study, the removal mechanism of polyacrylate-based paint is studied by fiber lasers. In addition, the effects of energy density on the quality of laser paint removal are investigated by scanning electron microscopy (SEM), and the relationship between the energy density and surface shape is studied. The mechanism of laser paint removal is studied using SEM, X-ray energy dispersive spectrometer (EDS), and X-ray photoelectron spectrometer (XPS). The results show that the quality of laser paint removal is considerably influenced by the energy density. When laser cleaning was performed once, the quality of laser paint removal improves with the increasing energy density. However, this quality slightly decreases because of the plasma shielding effect when the energy density is 12.56 J/cm ² and 13.60 J/cm ², respectively. When laser cleaning is performed twice, the quality of laser paint removal continuously improves with the increasing energy density. The combustion on the cleaning surface is weak owing to the enhanced laser-plasma-induced shock. The content of C on the cleaning surface increases, whereas that of O decreases. The morphology, element content, and chemical bonding of the cleaning surface indicates three types of cleaning mechanisms, including thermal combustion, pyrolysis, and plasma shock. Various coupling mechanisms are used to remove the polyacrylate-based paint from the surface of an aluminum alloy.