Abstract: TC4 alloys were manufactured by selective electron beam melting (SEBM) and subjected to ultrasonic surface rolling processing (USRP) in this study. The effects of USRP on the surface and microstructure of the alloys were investigated by optical microscopy, X-ray diffraction (XRD), and electron backscatter diffraction (EBSD). The corrosion behavior was analyzed with electrochemical testing methods. The results indicate that USRP causes the severe plastic deformation on the surface of SEBM-TC4 alloys, leading to the grain refinement, facilitating the formation of a gradient deformation layer (about 30 μm thick), and ultimately enhancing the surface finish and densification. In 3.5% mass fraction NaCl solution, the corrosion potential of the USRP-treated samples (−0.092 V_SCE) is significantly higher than that of the sandpaper-ground samples (−0.216 V_SCE), and the corrosion current density decreases by approximately 43.5%. Moreover, the passivation films on USRP-treated SEBM-TC4 exhibit a double-layer structure, with TiO₂ in the outer layer and (TiO₂+Ti₂O₃) in the inner layer. In summary, USRP improves the surface finish and densification of the metal, introduces the high-density dislocations in deformation layer to refine grains, and promotes the formation of a dense passivation film, notably improving the corrosion resistance of SEBM-TC4 alloys.