Recovery method of chemical polishing waste acid

The invention provides a chemical polishing waste acid recovery method which comprises the following steps: collecting phosphoric acid-containing wastewater obtained by first washing after chemical polishing, and enriching the phosphoric acid-containing wastewater in a chemical polishing washing water collection device as to-be-treated acid-containing wastewater; filtering the to-be-treated acid-containing wastewater to remove impurities to obtain filtered wastewater; the filtered wastewater is placed in a concentration tank to be subjected to low-temperature negative-pressure concentration evaporation, concentrated acid and distilled water are obtained, the pressure in the concentration tank is 10-20 KPa, the evaporation temperature in the concentration tank is 70-90 DEG C, and the specific gravity of the concentrated acid is larger than or equal to 1.7 kg/L; placing the concentrated acid in a stirring and flocculating device, adding a flocculating agent for flocculating with metal cations into the stirring