The invention discloses a treatment method of a high-concentration resin desorption liquid after the deep purification of wastewater, belonging to the field of resin desorption liquid treatment. The method comprises the following steps of: intercepting a high-concentration desorption liquid treated with anion exchange resin by using a nanofiltration membrane to obtain high-concentration nanofiltration intercepted liquid and nanofiltration penetrating liquid, wherein the nanofiltration penetrating liquid can be reused as a desorption agent after being oxidized; adding a coagulating agent into the produced high-concentration nanofiltration intercepted liquid to carry out coagulating sedimentation; carrying out Fenton oxidation or ozone oxidation on the supernatant liquid after coagulating sedimentation; adding alkaline liquid into the solution for further coagulating sedimentation after reaction; and returning the liquid after coagulating sedimentation back to the biochemical system of the biochemical tail water stage for further biological degradation. The high-concentration intercepted liquid treated by the method provided by the invention can return back for biological degradation, and the circular treatment of the high-concentration desorption liquid is realized. The method saves treatment cost, avoids secondary pollution and realizes the harmlessness, the reduction and the recycling of the resin desorption liquid.