An oil–water separation flotation column with a unique structure was used in oil–water separation fields. The oil–water separation flotation column contains the cyclonic separation and airflotation separation with advantages in the oily sewage treatment field such as low effective separation size, short separation time, large handling capacity, and low operating cost, especially in polymer-flooding-drive oily sewage treatment aspect. In this paper, the oil removal efficiencies of the cyclonic and airflotation sections of the oil–water separation flotation column were investigated. In addition, several operating parameters which impact separation such as feeding speed, aeration rate, circulating pressure, underflow split ratio, frother consumption were also investigated. The optimum operating parameters determined for the oil–water separation flotation column were a feeding speed of 1.50m³ h⁻¹, an aeration rate of 2.50m³ h⁻¹, and a circulating pressure of 0.28 MPa. A bottom flow diversion ratio of 95% and final effluent oil content of 16.49 mg L⁻¹ were also determined. Furthermore, three separation models for the cyclonic section separation, the airflotation section separation and the whole column separation were constructed.