Pollution　in　water　environments　hinders　both　social　progress　and　economic　development.　Wastewater　treatment　and　the　sustainable　use　of　water　resources　are　important　factors　in　solving　this　problem.　In　a　previous　study,　the　authors　proposed　a　process　that　used　photocatalytic　film　as　a　back-end　treatment　in　a　composite　iron-carbon　constructed　wetland　(WIC&PF)　to　restore　a　mildly　eutrophic　water　body.　This　method　has　strong　reoxygenation　effects,　and　can　efficiently　remove　pollutants;　these　are　qualities　that　have　not　been　mentioned　in　previous　studies　regarding　constructed　wetlands.　In　this　study,　the　authors　further　investigated　the　effectiveness　of　this　process　by　using　a　photocatalytic　film　as　a　front-end　treatment　for　a　composite　iron-carbon　constructed　wetland　(PF&WIC)　to　restore　a　mildly　eutrophic　water　body.　The　results　showed　NH4+-N,　TN,　TP,　COD,　and　chlorophyll　a　removal　rates　using　PF&WIC　of　79.1　+/-　6.6%,　76.8　+/-　6.5%,　77.0　+/-　5.4%,　77.3　+/-　7.2%,　and　91.7　+/-　5.6%,　respectively.　The　DO　concentration　of　the　water　body　increased　compared　with　that　of　the　effluent.　The　bacterial　species　and　their　abundance　in　the　lake　water　also　changed　significantly,　and　photosynthetic　autotrophic　bacteria　(Cyanobium　PCC-6307)　became　the　most　dominant　bacteria,　and　this　played　an　important　role　in　reoxygenating　the　water　body.　In　comparing　these　results　to　those　of　our　previous　study,　the　removal　of　pollutants　with　PF&WIC　was　close　to　that　with　WIC&PF,　but　the　reoxygenation　effect　of　PF&WIC　on　the　water　body　was　significantly　worse　than　that　of　WIC　&　PF;　thus,　WIC&PF　is　the　more　reasonable　choice　for　treating　eutrophic　water　bodies.