Mo₂NiB₂ based cermet coating was prepared on the surface of Q235 low carbon steel by atmospheric plasma spraying, and laser remelting was carried out at 300 W and 500 W power. The results show that the laser remelting method can significantly reduce the defects of the coating, make the microstructure more dense, and the weak mechanical bonding at the interface is transformed into a good metallurgical bonding. With the increase of laser power, the bonding strength and corrosion resistance of the coating are improved, the maximum bonding strength is 38.08 MPa, and the minimum corrosion current is 0.033 μA/cm²; But the hardness and wear resistance are reduced, the minimum hardness is 1781HV_0.2, and the maximum volume friction rate is 6.25×10^–5 mm³/(N·m). The hardness, bonding strength, wear resistance and corrosion resistance of the above plasma sprayed and two kinds of laser remelted Mo₂NiB₂ based cermet coatings were significantly higher than those of Q235 low carbon steel substrate.