Through the theoretically analyzing of the foundation of outburst prediction indexes and the existing prediction data of coal mine, a mathematics model was established with the dimension theories by considering with weights of dominant factors for ascertaining sensitive factors of coal seam. The established model and grey relevancy analysis were successfully verified in four coal mine of Pingdingshan and applied to Longshan coal mine. The sensitive indexes of Longshan coal mine was obtained by using the models. The technical approach put forward has a certain guiding meaning for analyzing and ascertaining the sensitive index which suitable for the conditions of coal seam for the prediction of coal and gas outburst.