Abstract: Mainly using secondary recycled water of Hohhot Zhanggaiying sewage treatment plant as the research object,on the basis of a large number of reclaimed water quality testing,the factor analysis method of dimensionality reduction and score function were used to carry on the reasonable evaluation and explore the seasonal variation characteristics,and put forward the reasonable use way of recycled water.The results showed that:the reclaimed water quality in summer was significantly better than that in other seasons,and reclaimed water had obvious seasonal and dayly instability.Sewage water was better in summer than in winter and seasonal fluctuations were obvious.This paper gives the efficient and reasonable utilization suggestions for the using of reclaimed water in Hohhot.