Abstract: As a special tooth form, the circular-arc end teeth serve as a critical connection component in aero-engines and gas turbines. To ensure mating accuracy and reduce stress concentration, the tooth flanks of circular-arc end teeth require a fillet operation. Traditional manual grinding fails to meet consistency requirements. Moreover, due to part clamping deviations and tooth surface deformations, theoretical tool paths cannot be directly applied in CNC machining. To ensure the quality of rounding the circular-arc end tooth profile, a geometric adaptive rounding method based on in-machine measurement is proposed. The shape and position information of circular-arc end tooth parts are obtained through in-process measurement, the part positions are accurately registered based on the point-to-plane distance metric, the actual end tooth profile is reconstructed by using the least-squares and B-spline surface fitting method, and the self-adaptive rounding machining tool path is obtained through the isoparametric mapping method. Rounding machining of the circular-arc end teeth of a certain model turbine disk shows that machining accuracy and consistency improved by 77% and 56%, respectively, compared to the pre-adaptive method, with machining errors less than 0.02 mm, meeting the actual process requirements for circular-arc end teeth.