The invention discloses a system and a method for treating and recycling regenerative waste liquid of macroporous denitrification resin. The system comprises a resin adsorption tank, a sodium chloridedosing tank, a waste liquid pool, a denitrification pool, a MBR (membrane bio-reactor), a recycling water tank, a nano-filtration membrane assembly, a reverse osmosis membrane assembly and a sodium hypochlorite generator; a macroporous denitrification resin adsorption technology is adopted to treat and send tail water in a sewage plant to the resin adsorption tank, a sodium chloride solution is utilized to regenerate, the regenerative waste liquid is collected into the waste liquid pool firstly, then enters the denitrification pool, followingly enters the MBR, and effluent flows back into therecycling water tank; the effluent is conveyed to the nano-filtration membrane assembly, and used for preparation of new resin regenerative liquid, concentrated water is partially drained out with the effluent in the resin adsorption tank, the rest concentrated water enters the reverse osmosis membrane assembly to be treated further, 98% and above dissoluble salt is retained, the produced water is directly drained out, the concentrated water directly enters the sodium hypochlorite generator to be electrolyzed, a disinfector is generated to disinfect and sterilize the effluent of the resin adsorption tank, and treatment and recycling of the regenerative waste liquid of the macroporous denitrification resin are achieved.