With the growth of oil exploration lasting, the water content of output fluids is increasing year by year, and in some oil wells the water content has reached to 95% and above, which brings new challenges to the existing treatment technology. To solve these problems, it is urgent to develop a new kind of oil-water separation technology to break through the "bottle-neck" of traditional technology. In this work, combined with the current demands of the oil and gas exploitation, the current situation of oil-water separation technology has been introduced systematically, as well as the characteristics of oily wastewater treatment technology, and the new demand and futural development trend of oil-water separation technology. At the same time, a new kind of pipe-type oil-water separation technology, developed by the Institute of Mechanics, Chinese Academy of Sciences, has been introduced in detail, which includes cylindrical pipe separation technology, vane-type pipe separation technology, and T-type pipe separation technology. Due to the technical advantages of new pipe-type separation technology, it can solve practical engineering problems successfully, such as heavy oil exploitation, submarine operation, and downhole separation. Furthermore, the development direction of oil-water separation technology has also been specified in this work.