In the real process of flood control decision-making, it is the precondition of improving the precision of flood forecasting and implementing timely, scientifical and reasonable decision-making of flood control scheduling that effectively organize and express the characteristics and information so as to realize the seamless connection and fully make the best use of the historic storm flood in real-time flood control decision-making . This paper gives an index system for the real-time and historic storm-flood information, analyzes the resemblance with mathematic methods, and eventually gets the historic storm-flood similar to the real-time one. By studying the tendency of the resemblance between historic and real-time storm floods, the tendency of real time storm flood will be predicted to provide the decision-making for the real-time flood control scheduling. This paper takes an example of the storm flood occurred in Songhuajiang Basin in 1998 to make the concerned analysis and gets a good result.