给出钢厂废水处理的流程和原理,针对钢厂废水处理具有量大、时变、非线性、大滞后等特点,提出采用模糊自适应PID控制的方法,进行废水处理中关键环节pH的控制.常规PID控制中整定比例、积分、微分3个控制参数是难点,为此在常规PID算法基础上引入模糊推理,根据pH的偏差值和偏差变化率实时调整3个控制参数.经比较可以看出,该方法在pH控制中具有较理想的控制效果. The flow and principle of waste water treatment in steel mill are given. According to the characteristics of steel mill waste water treatment such as large quantity, time-varying, non-linearity and large delay, a fuzzy adaptive PID control method is proposed to control the pH of key waste water treatment It is difficult to set three proportional, integral and differential control parameters in conventional PID control. Therefore, based on the conventional PID algorithm, fuzzy inference is introduced to adjust the three control parameters in real time according to the deviation of pH value and deviation. The method has better control effect in pH control.