A new method for the passivation of the cutting edge on flat-end cemented carbide (WC-8Co) cutter using ultrasonic vibration-assisted abrasive finishing was presented. Discrete Element Method (DEM) was used to model the abrasive finishing and ultrasonic vibration-assisted abrasive finishing of the cutting edge, respectively. It was found from simulation that not only the distribution but the value of the impact energy in the normal direction were better than that in the tangential direction, which would result in the high efficient erosion on the cutting edge within the same processing time as compared with that without ultrasonic vibration. It was also found from experiment that the passivation efficiency was improved by about 26% as compared with that without ultrasonic vibration, and the average milling force measured was about half of that without passivation on the cutting edge and its stability was significantly improved as well. (C) 2020 Elsevier B.V. All rights reserved.