Steel rolling waste acid complete resource recycling method

The invention relates to a corrosive waste water comprehensive treatment and resource recycling method especially used for treating pickling waste water, belongs to the field of environment protection, and specifically belongs to the field of circular economy. According to the corrosive waste water comprehensive treatment and resource recycling method, steel rolling waste acid is subjected to pretreatment, is delivered into a nanofiltration separation system taking high pressure gas as a pressure source, and then is divided into two parts, wherein water and reacted acids are discharged via a permeate liquid side, and ferric salts and macromolecule reduce erosion additives are discharged via a concentrated solution side; concentration of an obtained permeate liquid is increased to 37% via a HCl generator, and then is recycled to a pickling production line; an obtained concentrated solution is subjected to freezing crystallization-centrifugal separation so as to obtain ferric chloride and ferrous chloride products, and then the processed concentrated solution containing no ferric salt is taken as a reduce erosion additive for recycling. Steel rolling waste acid complete resource recycling is realized; product purity is high; impurity is less; and in addition, high pressure gas is taken as a high pressure tank pressure source, the stability of a pressure increasing process is ensured via gas compressibility, congenital protection effect on nanofiltration membranes is achieved, potential safety hazardof the corrosive waste water comprehensive treatment and resource recycling method is less, investment is less, and practicality is high.