This paper expounds a method for constructing the fire fighting simulative training system using the image processing technology and illustrates some key technical points of this system. An applied accelerative algorithm of gray scale Hough transform based on the information features of the target is proposed. This algorithm makes the burden of the operation decreased by four quantity degrees. The result of experiment shows that this method for detecting and extracting the center line of the fire fighting water column is fast and effective,and this system has proved to be a successful application of the image processing in the field of the fire fighting simulative training.