Abstract: In order to study the dynamic phenomenon of low gas content and low gas pressure in Xinmi coalfield,and solve the problem of the damage caused by low index dynamic phenomenon,the paper analyzed the tectonic evolution since Indo-China period based on the theory of regional tectonic evolution,and statistically analyzed 38 coal-gas dynamic events and 167 consistent coefficient f in Xinmi coalfield by combination with “Rules for Preventing Coal-Gas Outburst” and practical experience.The results showed that dynamic phenomenon in Xinmi coalfield was represented by low gas content,low gas pressure and consistent coefficient f below 0.3.The researches based on the theory of comprehensive hypothesis show that widespread development of deformed coal and small consistent coefficient are the deep reasons of this phenomenon.