Abstract: The research is based on the data measured in effect test of regional anti-outburst measures at 11202 coal mining face of Rongguang Coal Mine. The residual gas content and ash content of some coal samples were used to calculate the deviation between the calculated results and the measured values of gas content from other coal samples, and the main reasons of its occurrence are analyzed. The improvement measures of unified coal sample size and determination of underground coal sample weight are proposed. Through field experiments, it is proved that the improvement measures can effectively reduce the difference between the calculated result and the measured value and make the calculated result closer to the real value.