选择开封市惠济河水作为污灌引水点的样本水体，采用标准方法对灌溉水质进行监测分析。考虑到 TOPSIS 法在进行综合评价时的不足之处 , 提出了运用垂直距离代替欧氏距离进行评价 , 通过建立改进的 TOPSIS 模型，对污水灌溉安全性进行了评价研究。结果表明，开封市惠济河水质低于国家灌溉水质标准，直接用来灌溉或进行其他用途是不安全的，且重金属污染较严重。研究成果为水体的科学管理和污染防治提供决策依据，在水资源可持续开发利用中具有重要意义。

 First, the water of Huiji River in Kaifeng City was chosen as sample water body of the sewage irrigation, and water quality monitoring and analysis were conducted using standard methods. Considering the shortcomings of TOPSIS method to be used in carrying out a comprehensive assessment, we put forward to make use of the vertical distance instead of Euclidean distance . Through the establishment of improved TOPSIS model, the safety assessment of sewage irrigation was conducted. It is indicated that, the water quality of Huiji River in Kaifeng City was lower than GB5084-2005 standard and it is not safe to irrigate or do other things due to containing a variety of heavy metal pollutants. The present findings provide a scientific basis for water management and pollution treatment and it plays a great role in the sustainable use of water resouces.