An automatic oil-water separation and recovery device, which comprises a cylindrical tank, on the top of which exists an oil collector. The tank has an inflow pipe that links to a pre-separation regulating water distributor therein. The said water distributor is in the shape of an obconic bell mouth. At the lower part of the tank stands an outflow collector on which a bar-shaped oil-water separation unit is secured. The said outflow collector has an outlet. The said oil-water separation unit is made from stainless steel or plastic antipriming pipe firstly wrapped with unwoven cloth, and then taped with wires and outside the wires further wrapped with nonwoven cloth. All the cloth and wires are made of the same highly hydrophilic, oil-resistant material. The automatic oil-water separation and recovery devices described in this invention can be assembled together for separating and recovering ship-generated oily water. The assembled system works very well even though the oil content in the oily water fluctuates significantly. The average oil content in the treated water is about or lower than 5.0 m/L.