Abstract: Constructed wetland is an important means of water ecological restoration, pollution reduction, ecological space increase and biodiversity improvement. It is of great significance to restore the water ecosystem, provide ecological flow for water bodies, promote the recycling of regional reclaimed water and promote the construction of ecological civilization. On April 30, 2021, the Ministry of Ecology and Environment issued Technical Guidelines for Water Purification by Constructed Wetlands (hereinafter referred to as Guidelines), which aimed to guide local governments in their work related to water purification of constructed wetlands. The background and significance, compiling ideas, main contents and implementation suggestions of the Guidelines were mainly interpreted, and the technical points of the design, construction, acceptance, and operation and maintenance (O&M) of the constructed wetlands purification projects were systematically elaborated. Aiming at the current problems of inconsistent links in design, construction acceptance, operation and maintenance and emphasizing construction and neglecting maintenance of the constructed wetlands, based on the engineering practice and scientific research results, the important factors affecting the wetland function, purification efficiency and long-term operation were closely focused on in the Guidelines, the climate zoning throughout China was carried out, the design parameters in zoning was put forward, and the technical requirements for construction, acceptance, and O&M were refined, so as to provide ideological reference and technical support for the water purification of constructed wetlands in accordance with local conditions in China.