The invention discloses an acid and alkali recycled wastewater treatment system and method. The treatment system comprises a refine-processing acid and alkali recycled wastewater tank, a CO2 feeding system, and an ultrafilter system, wherein the refine-processing acid and alkali recycled wastewater tank, the CO2 feeding system, and the ultrafilter system communicates with each other; the ultrafilter system is connected to a primary reverse osmosis system; the primary reverse osmosis system is connected to a steam stripping and rectification system and a secondary reverse osmosis system, the steam stripping and rectification system is communicated with an electrolysis chlorine producing system; and the secondary reverse osmosis system is connected to a secondary reverse osmosis water-producing water tank and the refine-processing acid and alkali recycled wastewater tank. The acid and alkali recycled wastewater is mixed in the refine-processing acid and alkali recycled wastewater tank, the pH value of the wastewater is adjusted in the CO2 feeding system, the suspensions in the wastewater are eliminated in the ultrafilter system, then the processed wastewater is introduced into the primary reverse osmosis system, then the condensed water is introduced into the steam stripping and rectification system to carry out processing, the effluent from the steam stripping and rectification system is transported to the electrolysis chlorine producing system, the ammonia water is transported to an ammonia water recycling system to recycle, the producing water is processed in the secondary reverse osmosis system, then the processed producing water is collected, and condensed water is returned to the refine-processing acid and alkali recycled wastewater tank to carry out processing. The acid and alkali recycled wastewater treatment system and method can achieve comprehensive utilization and zero-discharge of acid and alkali recycled wastewater generated by a refine-processing system.