Through the study of the mechanism of removing heavy metal pollutants by constructed wetland, the selection methods of wetland plants and substrates were explored for the types of heavy metal pollutants. Combined with the research results of related process design, a constructed wetland system with Leersia hexandra Swartz as wetland plants and a mixture of red soil and zeolite as substrates was constructed. The design parameters of the constructed wetland system and the operating parameters such as hydraulic loading and influent concentration were studied. The research results can provide some reference for the technical development and application of constructed wetland treatment of heavy metal wastewater.