Abstract: Water level hold at specified locations within each reach is of the utmost importance for reliable and efficient management in a channel.A new algorithm for the control of unsteady flows in open channels is presented.An innovative control method is first analyzed,and then synthesized to construct a foreseeable module.The algorithm can thus be obtained by implanting the predicative module into a linear quadratic regulator(LQR).Using LQR,the canal operation problem can thus be reformulated as an optimal control problem,which regulates the gate discharge using the water level error as its constraints.The logical structure of the new algorithm is identified using an impulse response test,and the performance of the algorithm is tested on the platform of the "digital canal of the middle route of south to north water diversion project".The result shows that the algorithm performs well,is able to cope with the planned demand for large quantities of water,and is potentially useful for real applications.