Abstract: In view of disadvantages of long time-consuming and low prediction accuracy existed in prediction model of water inrush from coal seam floor based on traditional CART algorithm, a decision tree model based on improved CART algorithm was introduced, and the decision tree model was used to establish prediction model of water inrush from coal seam floor. The experiment results show that running time of the prediction model of water inrush from coal seam floor based on improved CART algorithm is reduced from 1.0411 s to 0.6125 s, and prediction accuracy rate is improved from 88.78% to 95.54%.