Wastewater　treatment　process　is　a　complex　industrial　process　with　disturbance　and　strong　nonlinearity,　and　it　is　difficult　to　accurately　track　the　pre-designed　dissolved　oxygen　(DO)　concentration　in　finite　time.　In　this　paper,　a　self-organizing　fuzzy　terminal　sliding　mode　(SOFTSM)　control　strategy　is　proposed　to　solve　this　problem.　First,　a　terminal　sliding　mode　controller　(TSMC)　is　designed　to　obtain　a　control　law　and　achieve　the　finite　time　tracking　of　the　pre-designed　DO　concentration.　Second,　a　self-organizing　fuzzy　neural　network　(SOFNN)　is　utilized　to　estimate　the　nonlinear　term.　Then,　the　pruning　strategy　without　pre-setting　pruning　threshold　is　designed　to　improve　the　approximation　accuracy　and　further　ensure　the　accuracy　of　control　performance.　Third,　an　adaptive　law　and　robust　control　term　are　designed　to　reduce　the　influence　of　uncertainty　and　approximation　error.　Moreover,　the　stability　of　SOFTSM　and　the　characteristic　of　finite　time　convergence　are　proved.　Finally,　the　proposed　method　is　tested　on　the　benchmark　simulation　model　no.　1　(BSM1).　In　contrast　to　other　existing　methods,　SOFTSM　can　realize　accurate　control　of　DO　concentration　in　finite　time.