Abstract: Risk prediction of coal and gas outburst is the key for controlling coal and gas outburst.The core of coal and gas outburst prediction is sensitivity of predictive index.In order to predict coal and gas outburst risk at drivage face of Yian mine,This paper studied the nature and application conditions of outburst prediction index,and statistical analyzed the interval distribution characteristics of outburst prediction index at drivage face and influencing factor of outburst prediction index.Combined with standard deviation and fuzzy prior relation decision,the outburst prediction sensitive index q andΔh₂,were determined ultimately at drivage face of Yian coal mine.