The invention discloses a chitin wastewater treating technique. Firstly parting of acid and alkaline cleaning wastewater is stored, integrated wastewater pH is adjusted via flow-control, then neutralization settlement, flocculation settlement, pre-aeration adjustment, A/O biochemical degradation and secondary precipitation for proteins are finished sequentially, and finally the wastewater reaches the standard and is discharged. The invention precipitates proteins in the wastewater in the maximal degree before biochemical treatment of the integrated wastewater by using the electric point precipitation character of proteins and the like, thereby avoiding to increasing of waste water disposal load caused by proteolysis, lowering difficulty of the waste water disposal, ensuring feasibility of biochemical system, simultaneously recycling reasonably proteins, resolving prominent problems of chitin wastewater pollution with the characters of superacid alkali and high salt and high protein, achieving highly effective and safe treatment of the wastewater and effective reclamation and utilization of the proteins, and ensuring sectional sustainable development.