To　control　the　dissolved　oxygen　concentration　and　nitrate　concentration　of　wasterwater　treatment　process　(WWTP),　we　propose　a　heuristic　dynamic　programming　(HDP)　method　based　on　the　echo　state　network　(ESN).　This　scheme　evaluates　the　current　policy,　and　then　the　HDP　controller　adjusts　the　current　policy　according　to　the　evaluation　results.　This　procedure　is　continued　until　the　optimal　policy　is　found.　Echo　state　networks　are　adopted　to　approximate　the　evaluation　function　and　the　optimal　policy.　To　ensure　the　availability　of　the　HDP　controller,　we　investigate　the　parameter　ranges　of　the　HDP　controller.　Experimental　results　indicate　that　the　ESN-based　HDP　controller　has　advantages　over　the　PID　controller　in　control　stability　and　control　precision.