Abstract: The analysis of the main controlling factors of coal seam permeability is of great significance to the development of gas drainage and coalbed methane. On the basis of reviewing the literatures, data and summary analysis, the influence of internal factors of coal seam and external factors of coal seam on permeability is discussed. The results show that the permeability of coal seam is affected by various factors, and the influence degree of each factor on the permeability is different. In the actual evaluation, the analysis is analyzed, and then the problems in some factors are discussed. Finally, it is pointed out that the effect of loading and unloading of axis comfining pressure of raw coal, complex and microfracture structures, different temperature segments (especially low temperature conditions), temperature and water coupling and the influence mechanism of filling particle size on permeability are the next research focuses in influence factors of coal seam permeability.