A method for improving denitrification performance of livestock and poultry wastewater by interplanting cyperus alternifolius and acorus calamus is realized by interplanting the cyperus alternifoliusand the acorus calamus on a subsurface flow constructed wetland, and periodically discharging effluent of a livestock and poultry wastewater digestion tank to the subsurface flow constructed wetland for purifying treatment, and comprises the following steps: 1) laying a wetland substrate; 2) interplanting high-stain-resistance wetland plants, wherein the high-stain-resistance wetland plants compris...
