Abstract: The paper studied relation between soft coal thickness and outburst of coal and gas, and got a conclusion that risk of outburst of coal and gas increases when soft coal thickness increases suddenly (rate of change ≥10%) or the thickness is more than 0.8 m over a period of time. In order to improve accuracy of outburst prediction, electromagnetic radiation is employed to analyze response regularity of soft coal thickness and electromagnetic radiation. The result shows that electromagnetic radiation of soft coal is higher than hard coal, and if soft coal thickness increases or sustains higher (≥0.8 m), value of electromagnetic radiation increases or sustains high too, outburst risk increases accordingly; there is a positive correlation between soft coal thickness and electromagnetic radiation, and the correlation coefficient is 0.824.