Ni-based superalloy coatings fabricated by laser melting deposition accumulate a large amount of residual stresses inside the coating, which adversely affects the microstructure and properties of the coating. The grade 4 Ni-based superalloy coatings reinforced with Nb and WC composite were prepared on 304NG stainless steel substrate by laser melting deposition technique, and the residual stresses inside the coatings were reduced by annealing treatment. The effects of annealing temperature and annealing time on the microstructure, microhardness, wear resistance, and tensile properties of the coatings were investigated. The results show that an increase in annealing temperature leads to an increase in the content of the softer matrix phase γ-Ni of the coating, a decrease in hardness, and the transformation of the discretely-distributed eutectic structure into a continuously-distributed network structure. Comprehensive analysis indicates that the coating after 700 °C/1 h/furnace cooling treatment exhibits the most excellent wear resistance and tensile properties. This is because the fatigue cracks generated during friction and wear in this coating disappear, and the wear mechanism transitions from fatigue wear to abrasive wear. At the same time, while ensuring the wear resistance of the coating, the plasticity of the coating is enhanced, achieving a synergistic enhancement of strength and plasticity.