Abstract The evolution processes of the structure and morphology of coal slime spherical particles in the process of combustion in an air atmosphere are examined in this work. A high-definition camera was used to capture changes in the macrostructure of the particles in the process of combustion, and a large amount of educt at the stage of homogeneous combustion was studied. The main component of the educt was graphite, as determined by X-ray diffraction(XRD),which demonstrated the process whereby the organic carbon molecule structures are transformed from a complicated and disordered condensed aromatic nucleus macromolecular structure to ordered graphite molecules with simple structures inside coal slime particles. Using a conducting N2 adsorption test and analysis, this study found that there were a number of mesopores and a handful of micropores inside the coal slime particles. The pore structures experienced a process that varied from complicated at the initial moment to simple, to complicated and finally to simple. Scanning electron microscope (SEM) photos proved the change process of the above pore structures and found the phenomenon whereby pyrolytic products filled the pores at the stage of homogeneous combustion.