The wastewater treatment plant has come into operation for four years,because the intake water caries frequently,analutical method has been limited and smooth operation of biochemical system couldn't be assured,the qualitu of outlet water is affected to a certain extent.Based on the data analusis coupled with practical operation,this article sums up the project of optimizing operation.It makes a foundation for the smooth operation of biochemical system and the assurence of ptoduct quality.