To effectively characterize the characteristics of the pore network of coal and to provide a realistic flow channel for flow simulation, a numerical reconstruction method of coal based on characteristics of the cleat system was proposed. Based on the real coal obtained through high-resolution micrometer CT, the cleat system characteristic parameters are defined and extracted. Then, a series of coals with different pore characteristics at the same scale and the same pore characteristics at different scales were reconstructed. Besides, the applicability of box dimension in calibrating the pore characteristics of coals was quantitatively analyzed. The results show that the coals reconstructed based on the method proposed in this paper can truly restore the pore characteristics of the real coal, especially the non-extension features of cleats; When the cleat system characteristic parameters remain consistent, the reconstructed coals maintain the same pore characteristics, with an average error of 3.37 % in the autocorrelation function, 0.78 % in the variation function and 1.94 % in the average percolation probability function. The box dimension can effectively identify the differences in pore characteristics of coals. At the same scale, as the distance between face cleats increases, the value of the box dimension of the reconstructed coals monotonically decreases, with a fitting slope of −0.22; At different scales, when the cleat system characteristic parameters remain the same, the value of the box dimension of the reconstructed coals is consistent, with an average relative error of 0.34 %. The research results provide a reasonable and effective flow channel for the microscopic/mesoscopic flow simulation of coalbed methane and provide a reference for the quantitative calibration of the pore characteristics of coals.