The figure of the pore size distribution of the SEM was gained by using scanning electron microscopy and Matlab graphics processing software and combining the conversion methods of pixel size.The anthracite coal of Handan Tao Yi Mining Bureau was studied.The average diameter of medium hole and large hole R1、R2 and the number N1、N2 were accessed by using aperture classification.The changes of pore structure changes in the law under the different conditions of coal combustion temperature were studied.