The treatment of wastewater is a complicated biological and chemical process, which can not be described precisely with a mathematical model. It is almost impossible to get a satisfactory control result when a traditional PID control method is adopted, for the parameters of the activated-sludge process are uncertain. The paper takes DO parameter controlling as an example, and proposes a human-simulated intelligent control strategy to reduce the fluctuation problem of DO parameter. Both the control rules and the structure of control system are presented. The simulation experiments shows that the control effect of activated-sludge process by HSIC is much better than PID control.