The work aims to study corrosion wear resistance of Ni-based cermet in seawater. 1.1 mm thick Ni-based cermet coatings were prepared by adopting laser cladding technology on 45# steel. Corrosion resistance of the coatings was contrastively analyzed with an electrochemical test system. Friction coefficient of the coatings was measured under conditions of dry friction and seawater environment with a reciprocating friction-abrasion testing machine. Surface morphology of the coatings and grinding cracks was analyzed with SEM, etc. Surface hardness of the Ni-based cermet coatings was uniform and nearly 3 times of the substrate. The hardness decreased dramatically from bond zone until it reduced to hardness of the substrate. In 3.5%NaCl solution, corrosion tendency of Ni-based cermet coatings was lower than that of 316L stainless steel and 316L surfacing layer, while corrosion rate of the Ni-based cermet coatings was between that of the two. The Ni-based cermet coatings significantly reduced friction coefficient (from 0.58 to 0.49) and wear loss (decreased by 50%) of the substrate under the condition of dry friction. Compared with dry friction experiment, the artificial seawater clearly reduced friction coefficient (from 0.49 to 0.37) and wear loss (decreased by 40%) of the Ni-based cermet coatings. The Ni-based cermet coatings exhibit good corrosion wear resistance in artificial seawater due to excellent corrosion resistance and high hardness. During wear process, contact status of friction interface is effectively improved, and wear resistance of the Ni-based cermet coatings is enhanced under cooling and lubrication effect of artificial seawater, and isolation effect of salts in artificial seawater.