Abstract: Based on the mine ventilation system, we develop the visual form by using AutoCAD VBA, and implement data and graphics data access by establishing the monitoring database of gas flow. The database of gas field analysis is established, and the statistical analysis of the gas emission from the roadway and the probability distribution is carried out. At the same time, the characteristic value of the gas flow samples of the roadway are analyzed, and the results are displayed in real time by means of interactive operation with AutoCAD, which is provided for understanding the whole mine gas emission and distribution. The gas flow analysis section is drawn by histogram, the least squares fitting curve, the χ²（k-1） distribution function testing the result. Combining Monte-Carlo method and random number generation method, the gas flow is randomly sampled to further verify the curve fit, and finally get the gas flow probability distribution function, so as to determine the distribution of gas flow in each roadway.