Advanced treatment method for oily sewage of finished oil depot

The invention provides an advanced treatment method for oily sewage of a finished oil depot. The method comprises the following steps: (1) adjusting the pH value of the oily sewage to 3-5 in an adjusting tank, adding the oily sewage into a catalytic oxidation tower through a lifting pump, adding a chlorine dioxide solution, aerating in the catalytic oxidation tower, and carrying out an oxidation reaction process on the oily sewage for 1-3 hours under the action of a catalyst in the catalytic oxidation tower, (2) pumping the oily sewage subjected to catalytic oxidation into an electrolytic reaction tank, and electrolyzing for 1-3 hours at the current density of 40-50mA/cm , (3) pumping the electrolyzed oily sewage into a flocculation tank, adding a flocculating agent, uniformly mixing, and standing for 1-2 hours, and (4) pumping the flocculated and precipitated oily sewage into a third-stage filter for filtering, and discharging after the effluent of the third-stage filter reaches thestandard. According to the