Abstract: The ultra-fast cooling equipment of hot rolling strip was introduced briefly. The deviation of ±0.5 m³/h of control target for cooling water flux was achieved quickly by coupling controlling the strip rolling parameters and setting cooling water precision. A calculation mathematical model of ultra-fast cooling system was constructed according to the hot rolling process requirement. The control accuracy of the intermediate and coil temperature can be limited within ±15°C of the target values by coupling with the optimal design of the system function and reasonable cooling strategy. Therefore, the ultra-fast cooling process of hot rolling strip becomes stable and reasonable. The field practice results showed that the system has high stability, reliability and high temperature hit rate, and it can improve significantly the quality and performance of the steels.