The work aims to further analyze the effects of gear surface integrity under ultrasonic-assisted machining (UAM) on anti-fatigue performance, and also promote the application of UAM to gear anti-fatigue manufacture. Based on advantages of UAM, comprehensive analysis was performed to such methods as ultrasonic hobbing, ultrasonic lapping, ultrasonic electrochemical gear machining and ultrasonic gear honing which were now applied to gear machining, respectively. On account of gear surface machining mechanisms in which residual stress and surface structure were controllable and by combining with the application of UAM to surface modification and surface strengthening, technologies of ultrasonic impact, ultrasonic shot peening and ultrasonic deep rolling reinforcement were analyzed in gear and other components, respectively. Compared with the conventional gear machining method, surface roughness Ra was greatly reduced, surface microstructure was changed and surface quality was significantly enhanced after UAM. Furthermore, surface was hardened owing to introduction of high-amplitude and large-depth residual compressive stress after ultrasonic strengthening, which inhibited propagation of cracks to some extent. Consequently, fatigue strength of the workpiece was improved, and gear anti-fatigue ability was enhanced. For that reason, UAM not only provides a new precise and efficient processing method for gear anti-fatigue manufacture, but also has great significance on perfecting domestic manufacture theory of high-performance gear and making progress in technology.