Grinding fluid & cutting oil are contained various chemicals. Waste fluid treatment causes huge disposal cost and heavy environmental load. This investigation proposes the electric rust preventive machining method system that water is used as machining fluid. However, there are various problems for this practical use. In this paper, using and re-using of machining water are considered. Water quality is different in various foreign regions for containing impurity ingredient varying with each area. Correspond to water difference, water purification and deionization is examined in developed machining water refine recycle system experimentally. Synthesized water that is likened to hard water is composed from refined water (pure water which is made by water recycle system). And, it is confirmed that synthesized water is refined to deionize by water recycle system. Moreover, 12.25L/min refined water is achieved. In addition, it is indicated that electric rust prevention is possible by refined water at least 1hour. However, high voltage and device twist is necessary.