Tool wear reduction is very important in cutting of ultra hard and brittle materials. In this paper, a tool-swinging cutting method was applied to reduce the wear of round-nosed diamond tools in cutting of tungsten carbide (WC). In this method, the geometrical center of the cutting edge was adjusted to be in coincidence with the rotation center of the B-axis table, and thus the cutting point could be changed along the cutting edge by swinging the tool about the B-axis center. Experimental results showed that the width of the flank wear land was greatly reduced compared to that in the conventional cutting. This work can shed light on ultraprecision machining WC parts without or with less need for subsequent polishing process.