An oil-water separation treatment system according to an embodiment of the present invention is an oil-water separation treatment system that separates a water-insoluble oil component from an oil-water mixed liquid, the system including an adsorption tower unit including at least one adsorption tower module, and a filtration unit including at least one filtration membrane module in that order. The adsorption tower module includes a tubular main body disposed vertically or horizontally, and a plurality of treatment layers which are divided from each other along an axial direction of the main body and in which a plurality of particles are enclosed. The filtration membrane module includes a filtration tank, a plurality of hollow fiber membranes that are disposed in the filtration tank and held in a state of being arranged to extend in one direction, and a holding member that fixes both ends of the plural hollow fiber membranes.
