Ternary precursor wastewater is usually divided into washing water, mother liquor, concentrated alkali washing solution, dilute alkali washing solution and other wastewater. The washing water and dilute alkali washing solution usually have pH = 9-11, salt concentration of 0.5% - 1%, ammonia nitrogen content of several hundred and contain a small amount of heavy metal suspension; Mother liquor and concentrated alkali washing liquor usually have high ammonia nitrogen content, high sodium sulfate content, pH = 11-13 and contain a large amount of complex nickel cobalt manganese.