The in-depth understanding of the storage and migration of coalbed methane requires qualitative analysis and quantitative characterization of the pore-fracture system in coal. In this study，the core samples of the No.3 coal seam in Mabidong Block in the southern Qinshui Basin was discussed in detail. The X-ray micro-CT scanning technology was applied，and three-dimensional digital model of the parent sample and the three-dimensional digital model of the child sample were proposed through low-resolution CT and high-resolution CT respectively. Based on that，the Avizo software was used to establish the pore-fracture system of coal sample，which realized the multi-scale quantitative characterization of the pore-fracture system. The results show that multi-scale pore structures develops in the No.3 coal seam of Mabidong Block in southern Qinshui Basin. Generally，the macropores are mainly C-type and the micropores are mainly E type. The overall pore connectivity is poor，and the fractures are isolated and distributed in sheets. According to the correlation of the mineral content between parent samples and child samples，it can be concluded that the large-scale fractures of the coal samples are mostly filled with minerals，which limits the percolation and production of the coalbed methane.