In order to improve the production efficiency,surface quality and reduce the grinding margins of Polycrystalline Diamond (PCD) compact cutting tools, a series of experiments of Low-speed Wire Cutting Electric Discharge Machining (LS-WEDM) for a PCD compact were taken. The PCD compact was cut by the WEDM for five times,then the surface roughness of cutting section, the machining quality of cobalt-rich interface layer and the edge of PCD layer were measured and discussed. The results indicate that the PCD compact shows better surface quality in its cutting section after multiple processing by LS-WEDM, and the machining quality is affected by diamond particle sizes greatly. For two kinds of PCD compacts, CTH025 and CTB010, the surface roughness are Ra=0.85 μm and Ra=0.57 μm,and the depths of the grooves of cobalt-rich interface layer are 16.3 μm and 5.7 μm, respectively. The size of the defect in the edge of PCD compact is matched with that of the diamond particle. The minimum grinding margins of PCD cutting tools can be controlled in 4-15 μm after LS-WEDM.