The invention discloses a tubular oil-water separation apparatus. The apparatus comprises a tube shell, the upper end of the tube shell is a separated water outlet, the lower end of the tube shell isa mixed liquid inlet, a swirler and a derotator which are coaxially arranged are mounted in the tube shell from top to bottom, a gap is arranged between the swirler and the derotator, each of the swirler and the derotator is provided with an outer guide vane and a central overflowing tube, the turning direction of the outer guide vane of the swirler is opposite to that of the outer guide vane of the derotator, the central overflowing tubes of the swirler and the derotator face each other, the lower end of the central overflowing of the swirler is connected with an oil outlet tube through a lower oil outlet bridge, and the upper end of the central overflowing tube of the derotator is connected with the oil outlet tube through an upper oil outlet bridge. The apparatus can improve the separation efficiency and stabilize the rotating flow field, can adjust the oil pump capacity for an inlet liquid with different oil contents to ensure a highest oil concentration, and can select an appropriate split ratio by controlling a regulating valve in a working cylinder in order to improve the oil-water separation efficiency.