This paper aims to improve the solid powder chromized layer thickness and wear resistance of 65Mn steel. The composite process of ultrasonic impact (UI) and solid powder chromizing (SPC) is carried out on 65Mn steel. The phase structure, thickness, and element distribution of the 65Mn chromized layer after UI + SPC treatments are studied by X-ray diffractometer (XRD), optical microscope (OM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The microhardness and friction- wear properties of the chromized layer after UI + SPC treatments are investigated by the microhardness tester and friction-wear tester. The results demonstrate that the thickness of the chromizing layer is 45 μm by the UI treatment and the thickness is 58 μm by the UI + SPC treatment, 13 μm thicker than the former. The surface structure of chromized layer is uniform and compact, and the main phase composition is (Cr,Fe)23C6, (Cr,Fe)7C6 and Cr2C. The surface hardness of the chromized layer reaches 1659HV by UI+SPC treatment, which is about six times of the surface hardness of the substrate, and the hardness distribution of the chromized layer show gradient descent from the surface to the inside. The surface chromized layer of the 65Mn steel has good anti-wear properties after UI + SPC treatment. The average friction coefficient is 0.170, and its wear weightlessness is about one-fourth of the that of the substrate. The dominating wear mechanism of UI+SPC sample is adhesive wear and oxidation wear, associated with slight abrasive wear. UI can effectively enhance the Cr atom diffusion property of SPC process and improve the thickness of chromized layer. Compared with SPC treatment, the wear resistance of the sample is significantly improved by UI+SPC treatment. With the addition of UI treatment, the wear mechanism of SPC samples changes from “abrasive + adhesive” to “adhesive, oxidation + abrasive”.