Abstract: Introduced a combination oil water separation system suitable to the scattered small fault block oilfield, that is, the simple dehydrating unit, it gathers up the techniques of ionic polarization, surface adsorption and membrane separation to carry out simple crude oil dehydration and sewage disposal, it has the characteristics of high efficiency, cheap price,convenient management, simple operation, being apt to install and unnecessary for chemical agent, it is the oil water separation equipment and the oil-bearing sewage disposal equipment wholly adopted physical method. Water content in the disposed crude oil approached that in the oil product, sewage quality reached to the standard of the injection water quality,so the produced sewage was injected back into the well, like this, it not only saved the cost for transporting oil with tank car, but also saved the expenditure of water cost, the economic benefit was extraordinarily obvious.