GB/T 18921-2002 stipulates the water quality standard for the regeneration of urban sewage for the landscape environment. The treatment and regeneration of urban sewage for the landscape can alleviate the shortage of water resources. The standard specifies the pH value, chemical oxygen demand, ammonia nitrogen, turbidity and other water quality index limits according to different scenarios of landscape water use, such as ornamental landscape water bodies and recreational landscape water bodies. Microbial indicators are also strictly stipulated to ensure the safety of use. At the same time standardize water quality monitoring methods and Frequency. Provide guidelines for the safe and effective use of urban sewage reclaimed water in the landscape environment, and help the recycling of urban water resources and the construction of the landscape environment.