Abstract: The reasons why the biological treatment system of wastewater is difficult to be automa-atically controlled is analyzed. The structure of the intelligent control system is introduced. The idea and principle of continuous and sequencing biological wastewater treatment system are illustrated. The status quo of the development and application of the artificial intelligent techniques, such as expert system, fuzzy logic and neural network, hybrid artificial intelligent technique as well as online sensors, in the biological wastewater treatment system is introduced. The further research and developing trends are aiming at different processes and levels. To select control variables and sensors, to abstract control regulations, to construct intelligent controller, to train simulating control system and to realize the final application and generalization from the demonstration engineering all are the future research content, and also show the development orientation.