The invention discloses a deep treatment method of coking wastewater. The method comprises the following steps of firstly adjusting pH of wastewater and filtering; reacting in a first-stage ozone reaction tower and a second-stage ozone reaction tower; carrying out ozonolysis in an enclosed intermediate water tank; treating in an aeration biological filtering tank; and introducing non-decomposed ozone into a tail gas absorber or destroyer. A treatment device mainly comprises a mixing sedimentation tank, the first-stage ozone reaction tower, the second-stage ozone reaction tower, the aeration biological filtering tank and conveying pipes, wherein the conveying pipe between the mixing sedimentation tank and the first-stage ozone reaction tower is connected with a multi-medium filter; and the conveying pipe between the second-stage ozone reaction tower and the aeration biological filtering tank is connected with the enclosed intermediate water tank and the tail gas absorber or destroyer is connected with two ozone reaction towers and the enclosed intermediate water tank. By combining ozone catalytic ozonation and the aeration biological filtering tank, non-biodegradable organic substances in wastewater are oxidized by virtue of ozone and mineralized or partially oxidized into easily degradable small molecular organic substances and the small molecular organic substances can be subjected to subsequent treatment by virtue of cheap organisms in the aeration biological filtering tank.