The Samples of Polycrystalline Diamond (PCD) Cutting Tool Were Machined by Adjusting the Main Parameters of Electrical Discharge Machining (EDM). after the Machining, the Phases Were Analyzed by X-Ray Diffraction Analyzer and the Surface Layer Microstructure Were Observed by Scanning Electronic Microscope. the Fundamental Component of Machined PCD Cutting Tool Affected Layer Was Obtained and the Reason of Bring Affected Layer Was Analyzed. the Relationship Curves between Pulse Width, Working Electric Current and Depth Affected Layer, Surface Roughness Were Summarized. the Relationship between PCD Cutting Tools that Was Machined by EDM and Cutting Tool Flank Width, Workpiece Surface Roughness Were Analyed.The Results Showed that to Adjust Electical Discharge Machining Parameter, such as Pulse Width and Machining Electric Currents, Can Reduce the Depth of Affect Layer and Extend the Service Life of PCD Cutting Tool.These Researches Provide Valuable Test Reference for Drawing up Electrical Discharge Machining Technics of PCD Cutting Tool and Cutting Tool’s Life.