Various techniques to control microstructures and performances have been developed to address the problems of microstructure defects, residual stress, and anisotropy in metal additive manufacturing components. Based on the recent work performed in associated with additive manufacturing assisted by ultrasonic energy field, this paper analyzes the “liquid–solid” dual effect of ultrasonic impact, and summarizes the influence of ultrasonic impact treatment on the microstructure, surface roughness, microhardness, residual stress, corrosion resistance and other properties of additive metal materials. The results show that ultrasonic energy field ensures that the internal microstructure and grain size are significantly refined, the porosity is reduced, and the corrosion resistance is improved. At the same time, the microhardness of the additive component increases, and the residual tensile stress is transformed into residual compressive stress that is beneficial to the mechanical properties of the parts.