Comprehensive treatment method for mixed waste water containing chromium and heavy metal

The comprhensive treatment method of mixed waste water containing chromium and heavy metal includes: the chromium and heavy metal contains mixed waste water which is not undergone the process of acidification treatment is pumped into reaction container with adsorption reduction indication agent to make reaction, at the same time the flowmeter is used for controlling the added acid or alkali quantity in the chemicals box, and the test paper is used for detecting pH 8-9 in the reaction continaer from detection value of the reaction container and detecting colour change of adsorption reduction indication agent at isoelectric point to control treatment effect of said mixed waste water, and the reacted water is discharged from upper portion of reaction container through overflow tube, precipitated, filtered and discharged, the filter residue can be recovered to make treatment.