<p>Laser cladding technology has garnered significant attention in material surface modification due to its unique advantages. In the nuclear industry, 2205 duplex stainless steel is widely used, and enhancing its surface properties is of critical importance. This study investigates the effects of ultrasonic field assistance on the microstructure and properties of laser cladding layers. Using a coaxial powder feeding laser cladding system, spherical nickel-coated carbon powder was deposited onto a 2205-duplex stainless steel substrate, with an ultrasonic field applied during the process. The microstructure, phase composition, mechanical properties, wear resistance, and high-temperature oxidation resistance of the cladding layer were systematically analyzed to elucidate the underlying mechanisms of ultrasonic field influence. Online vibration detection and analysis further revealed how ultrasonic power modulates the microstructure and characteristics of the clad layer. The results demonstrate that while the ultrasonic field does not change the phase composition, it significantly refines grain size as the ultrasonic generator power increases. Compared to conventional laser cladding, ultrasonic assistance leads to substantial performance enhancements: a 20% increase in hardness, a 72% reduction in friction coefficient, a 78.2% decrease in wear volume, and a 55.6% improvement in oxidation resistance. These improvements are attributed to microstructural optimization induced by ultrasonic vibration. This study provides both theoretical insights and technical guidance for the practical application of ultrasonic-assisted laser cladding in the related research.</p>