Based on the spectrum and image analysis,a method of predicting the converter end-point was proposed. A flame light and video capture system was designed to analyze the data with the edited codes. The result shows that the light intensity and the image characteristic information have the remarkable change law in the steelmaking blowing process,which coincides essentially with the experience steelmaking. Through the statistics reverse analysis,some characteristic parameters were selected,and then the end-point time mathematical model was established by the use of the multivariate regression analysis method. The experimental results indicate that the model passes the significance test,and the predication accuracy is 90.4% when the measurement error is less than 4 second. The model is stable and provides a convenient method to predict the converter steel-making end-point on line.