In recent decades, wetland treatment systems have been widely used in sewage treatment, and pollutants can be removed through the retention, sedimentation, absorption, and transformation of substrates, plants, and microorganisms. Wetland plants play an indispensable role as an important part of it. This article briefly introduces the basic types and principles of phytoremediation. The construction of artificial wetlands is the main cornerstone of building a good ecological environment, and protecting the ecological environment is equivalent to protecting our homeland. In recent years, my country has gradually applied the wetland treatment system to sewage treatment, and removed harmful pollutants through the transformation of plants, microorganisms, and substrates.