To explore the effect of mixed plants on the eutrophic water，an outdoor static simulation test with the same conditions was carried out.Iris pseudacorus and Canna indica were selected for the artificial floating island with different ratios.The results showed that in the static condition，the average removal rate of TN，TP and CODMnwere 83.23%，84.12%，67.76%.It is showed the removal rate of water nutrients is highest when mixed plant is iris：canna=3∶1.