In　order　to　improve　the　control　performance　of　the　dissolved　oxygen　(DO)　concentration　and　nitrate　nitrogen　(SNO)　concentration　in　a　wastewater　treatment　plant　(WWTP),　an　optimal　control　strategy　based　on　iterative　adaptive　dynamic　programming　(ADP)　algorithm　was　proposed.　It　only　need　the　input　and　output　of　the　non-linear　dynamics　model　of　the　control　system,　and　approximate　the　performance　evaluation　index　and　optimal　control　strategy　by　networks　identifying　the　control　system.　The　learning　algorithm　of　controler　was　implemented　on　line　in　the　benchmark　simulation　model(BSM1).　Finally,　the　experiments　validate　the　effectiveness　of　the　proposed　control　strategy　in　improving　the　control　precision　and　system　robustness　compared　to　the　traditional　PID　control　strategy.　©　2018,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.