The complex post-explosion environment in a coal mine can induce multiple methane explosions, in which coal dust explosion residues might be involved. To investigate the explosion possibility and characteristics of coal dust explosion solid residues, tests were carried out in a 20 L explosion device. The results show that the collected coal dust solid residues remain capable of exploding. Unexpectedly, the explosion intensity of residues is still strong, despite being weaker than that of coal dust: the residues are characterised by a slower flame propagation speed and a lower heat release rate than that of coal dust. The re-explosion product analysis shows that more holes appeared and the elemental contents of carbon, oxygen, and nitrogen decreased. Proximate analysis and FTIR analysis reveal that fixed carbon, instead of volatile matter and chemical bonds, in these residues is further combusted in the re-explosion process. The research results are of significance when assessing explosion hazards arising from coal dust explosion residues in a coal mine.