Transverse-flow CO2 laser is used to strengthen the NiAl/nano Al2O3 electroless composite plating by laser remelting. Then high-temperature oxidation resistance experiments at 800 ℃ of laser remelted coating are carried out. The surface profile, microstructure and high-temperature oxidation resistance of plated coatings before and after laser remelting are analyzed by energy dispersive X-ray spectrum (EDS), scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The high-tempetature oxidation resistance of laser remelted coating is remarkably improved compared with the original composite plate and substrate. On the one hand, the intermetallics NiAl2O4 and Ni0.77AlFe0.23 of laser remelted coating contribute to enhance high-temperature oxidation resistance at 800 ℃; on the other hand, a dense and continuous oxidation film is formed on the coating surface after laser remelting.