The diversities of soil bacterial communities in the Phragmites australis, Phalaris arundinacea, and non-plantation constructed wetlands were compared and analyzed by through high-throughput Illumina sequencing. At the phylum level, the ten dominant bacterial phyla in the three types of constructed wetlands were the same. At the genus level, the three most dominant bacterial genera in the three types of constructed wetlands were the same. The non-plantation constructed wetland (Nop-cw) had the highest diversity of soil bacterial community. The introduction of P. australis or P. arundinacea did not increase diversity of the soil bacterial communities in the constructed wetlands but greatly changed the compositions and potential function of the soil bacterial communities, especially some bacterial genera involved in pollutant removal. So it was predicted that the P. australis constructed wetland (Pau-cw) had a larger capacity for the removal of heavy metals and sulfur than the P. arundinacea constructed wetland (Par-cw), and the nitrification capacity of the P. arundinacea constructed wetland was stronger than that of the P. australis constructed wetland. The above results not only clarified the differences among the soil bacterial communities of the constructed wetlands with different plants in terms of diversity but also revealed the decontamination mechanism of the constructed wetlands to some degree.