Using　microalgae　for　rare　earth　elements　wastewater　treatment　has　been　proved　to　be　effective,　however,　the　technology　is　challenged　by　the　unstable　performances　caused　by　the　changeable　wastewater　qualities　and　natural　conditions.　In　this　study,　a　corrected　response　surface　methodology　was　first　used　to　provide　an　optimized　operation　strategy　for　the　application　of　wastewater　treatment　using　microalgae,　by　investigating　the　effects　and　interrelations　of　three　main　factors　including　temperature,　illumination　intensity　and　microalgae　concentration,　taking　rare　earth　elements　wastewater　in　Southern　Jiangxi　as　an　example.　Nine　models　were　obtained　using　nine　types　of　wastewater.　The　models　were　then　modified　by　categorizing　wastewaters　into　two　classes　(error　range　＜　12%)　according　to　their　initial　ammonia　nitrogen　concentrations.　The　optimal　conditions　for　ammonia　nitrogen　removal　in　class　I　and　class　II　wastewater　were　as　follows:　temperature　of　21.0　and　23.6　C,　illumination　intensity　of　46.8,　45.3　LX　%,　microalgae　concentration　of　1.64　and　1.67　g　dry　weight/L.　The　results　are　confirmed　by　stable　operation　of　a　continuous-flow　photobioreactor　for　more　than　122　days.　The　amount　of　microalgae　required　to　treat　wastewater　under　natural　conditions　is　1.5-1.8　g　dry　weight/L　estimated　by　the　corrected　model.　It　implies　that　nearly　16,710　kg　and　46,520　kg　of　ammonia　nitrogen　could　be　removed　from　two　typical　wastewaters　with　optimal　microalgae　dosage　in　2020.　The　results　demonstrated　that　corrected　response　surface　methodology　provides　a　powerful　approach　for　optimizing　the　operational　conditions　for　wastewater　treatment　by　microalgae.