The invention discloses a treatment device for stainless steel cold-rolling pickling waste water. The treatment device comprises ultrafiltration equipment, reverse osmosis equipment and a solar evaporator group, wherein the solar evaporator group comprises at least one solar evaporator, an input terminal of the solar evaporator group is connected with an output terminal of the reverse osmosis equipment, the solar evaporator group is used for carrying out distilling concentration on nitrate-containing waste water input to the solar evaporator group so as to separately discharge distilled water and nitrate-containing concentrated liquor from a distilled water discharge opening and a concentrated liquor discharge opening. Correspondingly, the invention also discloses a treatment method for the stainless steel cold-rolling pickling waste water. According to the treatment method and device for the stainless steel cold-rolling pickling waste water, disclosed by the invention, total nitrogen can be effectively removed from the cold-rolling pickling waste water through the distilling concentration of nitrates, the nitrates in the waste water are changed into the valuable from the waste, the cold-rolling pickling waste water can be discharged after reaching standard, and the waste harmful to environment is fully utilized, so that the aims of saving energy and being environment-friendly and economical are achieved.