The basic Principles and status of Compound ECM/EDM are described inthis paper. Finally it focuses on the finishing operation of this method, which is the gapprocess, optimization of the flow field and parameters. It has been found that microsparksbreak down the anodic film. It leads the intensive nonlinear action of anodic dissolutio andresults in not only improvement the surfase finish but also increase the accuracy. It ispromises for applications in precision die-sinking.