Wastewater treated on the surface of aluminum profiles includes pre-treated degreasing and acidic washing water, alkaline washing water after alkali corrosion, acid washing water after acid etching, acid washing water after oxidation, and Ni2 +, Sn2 +, Acidic washing water, waste acid, waste alkali and a small amount of waste water from electrophoretic painting and ion exchange. The wastewater is acidic after mixing, and contains cations such as Al3 +, Ni2 +, Sn2 +, Sn4 +, Na +, Cr3 +, and anions such as SO42-, F-, NO3-, Cl-, AlO2-, Ac-, etc. Organic substances such as resin. The waste liquid includes waste sulfuric acid produced by degreasing and neutralization, waste sulfuric acid produced by oxidation, waste sulfuric acid produced by oxidation, waste liquid produced by coloring, waste acrylic acid produced by electrophoretic painting, and waste liquid containing Ni2 + and F- produced by sealing.