Abstract: An automatic control system of flow capacity and water - level for model test was independently developed because of its expensive pr ice. The system consists of an electromagnetic flow meter with high accuracy, a n electric - regulation butterfly valve, a flow controller, a precision tracking water - level meter, a water - level controller and a main controlling computer. T he hardware structure of flow and water - level controller bases on single - chip microcomputer and uses double integral, high accuracy A/D conversion chips for d ate acquisition, and the software adopts embedded operation systems and self - ad justing PID arithmetic units. This system can improve the experiment methods, en hance the accuracy of measurement and control, and suit to every kind of complex bad working conditions with high reliability and stability. It has been success fully applied in production practice, and may be popularized in hydraulic model and river model experiments.