Abstract:To find out the influence of deep-hole controlled pre-cracking explosion on microstructure of coal,a field test of deep-hole controlled pre-cracking explosion was carried out in a mine located in south China. In the test,the microstructures of some coal samples,taken from different spots that were 3.0 to 9.7 m away from the explosive hole,were observed carefully with ASAP–2010(automated surface area analyzer–2010). Besides,the performance of gas drainage was studied. The results showed that,with the increment of distance from explosive hole,the Langmuir surface area and BET surface area decreased linearly. At the spot 9.7 m away from explosive hole,Langmuir surface area and BET surface area decreased 68.8% and 15.26% respectively. The volumetric ratio and area ratio of micropores decreased at first and increased then. On the contrary,the volumetric ratio and area ratio of small-pores and mid-size-pores increased at first and decreased then. The volume ratio of penetrating pores increased a little at the beginning and decreased then. The peak value,which was 26.88%,was 3.9 m away from the exploding hole. After explosion,the highest gas drainage volume increased 36%,and the total gas drainage volume in the first 15 days increased 93%. The optimum distance among exploding holes of deep-hole controlled pre-cracking explosion should be between 10 to 12 m.