Abstract: In order to study the spatial structure characteristics of gas occurrence in primary coal at micro scale, mercury injection test, N₂ adsorption/desorption experiment and X-ray CT technology were used. The development characteristics of multiscale pore clusters of original structure gas coal and coking coal were quantitatively analyzed and image recognized, and the development characteristics of multiscale pore cluster were discussed. The results show that: SQY coking coal has few seepage pores and abundant adsorption pores, while XG gas coal has wide distribution of seepage pores and small pore size defects. The balanced development of multistage pore clusters is the structural basis of large amount of gas occurrence and efficient seepage. XG gas coal seepage pore clusters and SQY coking coal adsorption pore clusters developed in large quantities have complex spatial structures, and the volume advantage is an important incentive. X-ray CT technology can accurately identify the pore morphology of coal. XG gas coal mineral distribution does not enhance the spatial heterogeneity of multistage pore clusters. A large number of minerals developed in SQY coking coal occupy the matrix space, which is the internal factor leading to poor development of multistage pore clusters and strong heterogeneity.