The utility model relates to an oil -water?separator for production of cis -butenedioic anhydride solvent, the device are equipped with water oil separating case, raceway, defeated oil pipe, water collecting vat and oil collection groove, are equipped with inlet, oil -out and delivery port on the water oil separating case, and the water of water oil separating case separation passes through the leading -in water collecting vat of raceway through the delivery port, the oil of separation through the oil -out through the leading -in oil collection groove of defeated oil pipe, in the water oil separating case box by inlet to oil -out direction be equipped with in proper order the top all separate with the box, just with S flow region board, water oil separating board and the profit division board of the perpendicular setting of liquid flow direction, the utility model discloses with the effective layering under the different proportions of organic mixture of water and transition layer, the continuous enrichment of oils, reach the purpose of separation, and the material purity of retrieving is high, can continue to return the utilization, can provide more thorough that the sufficient separation time just can be with water and separating of oil, but the device continuous operation, automatic operation.