: Cyclic activated sludge system (CASS) is an advanced sewage treatment technics. This paper presents a computer control system,which has a better adaptability and strength,and easy to maintain.

• 循环活性污泥系统(CASS)是一种先进的污水处理工艺，本文提出了实现CASS工艺的一种计算机自动控制系统，该系统具有较好的灵活性和较高的可靠性、可维护性。