There are three treatment methods for reclaimed water due to different purposes: 1. one is to treat it to the standard of drinking water and directly reuse it in daily life, that is, to realize the direct recycling of water resources. This treatment method is suitable for areas with extreme lack of water resources, but the investment is high and the process is complex; 2. the other is to treat it to the standard of non potable water, which is mainly used for water not in direct contact with the human body, such as toilet flushing, ground and car cleaning, greening sprinkling, fire fighting, industrial common water, etc. This is the usual method of reclaimed water treatment. 3. in industry, the reclaimed water reuse technology can be used to reprocess the industrial sewage that meets the discharge standard. Generally, softener, RO, edi/ mixed bed and other equipment will be added to make it reach the level of softened water, purified water and ultra pure water. It can be recycled in industry to save capital and protect the environment.