针对液位控制设计一种基于施耐德Twido系列PLC的PID控制系统，可以在线实现PID参数自调整，使液位控制系统的响应速度加快，超调量减少，过渡过程时间大大缩短，具有较强的鲁棒性和稳定性。关 键 词： 液位控制；自整定；Twido PLCAbstract：Liquid-level control system is a prevalent problem of industrial processcontrol. Specifically for liquid-level controls, designing a PID controls system baseon the Twido PLC, it can realize PID parameter Self-tuning on line, make liquid-levelcontrol systematic speed of response quickly, decreases the overshoot, greatly shortenthe response time, with stronger robustness and stability.Key word: liquid-level control; Self-tuning; Twido PLC