In order to solve the problems of start-stop frequently for lift pumps, overflow accidents for collection wells and high energy consumption for pump units, an optimal control system is proposed based on a variable-parameter PID control algorithm and lift pump station group polling and is applied to a sewage treatment plant of Zhuzhou. The actual operation results show that the control system adapts to the change of water inflow and achieves good effects in reducing the start-stop times, avoiding the overflow of collection wells, reducing the energy consumption and ensuring the production safety.