Method and device for pretreating thickened oil refining sewage

The invention provides a method and a device for pretreating thickened oil refining sewage. The method comprises the steps of homogeneous sedimentation, emulsion breaking oil removal and sulphur removal, coagulating sedimentation sulphur removal, primary ozonation and secondary catalytic ozonation, for pretreating high-oil-content and severely-polluted sewage generated in a thickened oil refining process. In the steps of the homogeneous sedimentation, the emulsion breaking oil removal and sulphur removal, and the coagulating sedimentation sulphur removal, a thickened oil resource is recovered to the greatest extent mainly by physical and chemical means, and pollutants such as mud residues and SS (suspended solids) in non-dissolved states are removed; then a water sample is further subjected to the primary ozonation and the secondary catalytic ozonation; the acute catalytic ozonation of water is reduced; and the biodegradability is improved. The pretreated sewage meets a water inlet requirement of a biochemical treatment technology in a general oil refining sewage plant; and multiple functions such as recovering the oil resource, and eliminating foul gas pollution can be achieved in the process of pretreating the thickened oil refining sewage.