To improve the wear resistance and corrosion performance of a heat-exchanger tube assembly for solar thermal-power generation, the surface of 321 austenitic stainless steel, which is widely used in heat-exchanger components, is strengthened in this study to address the issue of component failure caused by severe wear and corrosion. First, a Ni60/WC alloy coating is prepared on a 321 stainless-steel substrate via high-speed laser cladding. Based on the laser power, scanning speed, and powder feed rate as influencing factors in addition to the hardness and dilution rate as characteristic variables, the process parameters are optimized via a single-factor test. Subsequently, the phase composition of the coating is analyzed based on the X-ray diffraction (XRD) pattern, whereas the morphology and elemental distribution of the coating are analyzed using scanning electron microscopy (SEM). Finally, a set of optimal process parameters is obtained by analyzing the macroscopic morphology, XRD pattern, and SEM results The optimal process parameters are as follows: laser power is 1000 W, scanning speed is 10 mm/s, and powder feed rate is 3.5 g·min^-1. The coating phase primarily comprises a solid solution (γ-Fe, Ni) as well as carbides M7C3 and M23C6. The wear resistance of the coating improves significantly and the average friction coefficient of the cladding layer is approximately 0.4, which is lower than that of the matrix (0.8). The wear of the coating is 2.75 mg, which is approximately 65% of the substrate wear (i.e., 4.24 mg). The self-corrosion potential of the coating is -0.674 V, which is higher than that of the matrix (i.e., -0.754 V). The arc radius of the coating is larger than that of the substrate, indicating that the coating can reduce the corrosion rate of the substrate. The highest hardness value of the coating is 608 HV_0.2, which is approximately 1.91 times that of the matrix, indicating the high corrosion resistance of the Ni60/WC alloy coating. In summary, the Ni60/WC alloy coating significantly improves the wear resistance and corrosion properties of 321 stainless-steel surface.