In the study, constructed wetlands with 3 plant species (Canna indica, Acourus calamus and Luthrum salicaria) were respectively built to obtain the optimal treatment conditions. In the treatment experiments, various factors were respectively arranged as follows: C/N/P (50/10/1, 25/5/1, 25/5/2, and 25/5/3), salinity (0.5, 1 and 2), and the HRT (1, 2, 3 and 4 d). The removal rate of TN, TP and COD in constructed wetland, the content of NH₃-N, NO₃-N, NO₂-N and PO₄^3- in influent and growth parameters of three plants were determined. The results showed that:When the HRT=4 d, the influent salinity of 1.0 and C/N/P was 25/5/2 (COD=50 mg/L, TN=5 mg/L, TP=4 mg/L), the highest removal rates of TN (90%), TP (97%) and COD (65%) were reached;Among the different plant and substrate combinations, the Canna indica wetland device had the best removal effect, the chlorophyll (SPAD value) and superoxide dismutase in Canna indica were relatively high, and the content of malondialdehyde is lower, respectively, 40.6, 1 212 U/g and 2.45 nmol/g, and the amino acid content was 1.82%;With influent salinity of 1 and C/N/P(25/5/2), the microbial community structure in the constructed wetland was optimized, and the dominant flora was Proteobacteria, which is a common functional flora in wastewater treatment. Therefore, Canna-constructed wetlands can treat low-salinity aquaculture wastewater, strengthen the treatment effect of constructed wetlands, improve the synergistic decontamination and salinity tolerance of plants-microorganisms, and provide technical support for coastal water body restoration.