Treatment method of DCB neutralization wastewater

The invention provides a treatment method of DCB neutralization wastewater, which comprises the following steps: S1, extraction: mixing the DCB neutralization wastewater with a first extraction solvent for mixed extraction, and standing and settling to obtain an upper-layer second extraction phase and lower-layer wastewater; s2, back extraction: mixing the second extraction phase with dilute sulphuric acid for back extraction, and standing and settling to obtain an upper-layer third extraction solvent phase and a lower-layer dilute sulphuric acid phase containing an o-chloroaniline sulfate crystallization material; s3, filtering: filtering the dilute sulphuric acid phase containing the o-chloroaniline sulfate crystal material at the lower layer obtained in the step S2 to obtain crude o-chloroaniline sulfate and filtrate dilute sulphuric acid; and S4, distillation recovery: adjusting the pH value of the crude product o-chloroaniline sulfate to alkalescence, and recovering o-chloroaniline ...