A method for treating highly concentrated resin-desorption liquid generated from wastewater deep purification, including channeling the highly concentrated desorption liquid generated from anion exchange resin treatment through a nanofiltration membrane, the liquid being separated into nanofiltration permeate that can be reused as the desorption agent and highly concentrated nanofiltration retentate; adding a coagulating agent to the highly concentrated nanofiltration retentate to generate coagulation-precipitation; subjecting the supernatant formed after the coagulation-precipitation process to Fenton oxidation or ozone oxidation; after the reaction, adding to the liquid an alkali solution for further coagulation-precipitation; then channeling the liquid so treated back to the biochemical system of biochemical effluent treatment for further biodegradation is provided. The recycled treatment of the highly concentrated desorption liquid consequently reduces the treatment cost and prevents secondary pollution by realizing innocuous treatment and reclamation of resin-desorption liquid as well as reduction of its total volume.