Abstract: Firstly,according to the mechanism and actual condition of coal and gas outburst,considering various factors of gas emission,a comprehensive and scientific coal and gas warning index system is built,and then the coal and gas outburst warning system software is developed based on VB programming and SQL Sever2000.The system software is used with actural gas emission data,and the result shows that all of the warning indexes are abnormal in early stage of coal and gas outburst;the concrete features are that the point cloud in sky chart is more denser;the average line of G line chart is generally upward and shows " three yang" trend many times;the moving average line repeatly sends effective signal of crossing and multi-average line arrangement,the variation quantity of amplitude increases,which is showed as upward trend and multiple pulse on the gragh;the change frequency of gas concentration is increased trend,which achieves the warning of coal and gas outburst.