Based on the occurrence of coal and gas outburst on the eve of a long period of time,  abnormal gas concentration monitoring data but not overrun, the ignoring problem due to it, the gas concentration monitoring data of the moving average, the rate of change and variance , the three indexes of comprehensive analysis of variance was put forward. Using the monitoring data of gas concentration prediction method of coal and gas outburst to implement coal and gas outburst forecast in working face. The examples proved that by this method can realize coal and gas outburst forecast in the working face.