Abstract: Coal gasification is a key technology in coal chemical industry, but if the residue produced is not properly treated, it will cause damage and pollution to soil, water and atmosphere. The composition and structural characteristics of the residue from a coal water slurry gasifier were explored using proximate analysis and FT-IR testing. Additionally, the pyrolysis and combustion characteristics of the residue were examined under inert and oxidative atmospheres. The results indicate that after the gasification process, the gasification residue (coarse and fine) still contains a small amount of volatile matter that is not completely decomposed, and the fixed carbon is not fully converted. Among them, the volatile matter and fixed carbon mass fraction of the fine residue are 9.52 % and 16.25 %, respectively, which are both higher than those in the coarse residue (1.15 % and 0.03 %). FT-IR analysis shows that after gasification, some functional groups in raw coal do not decompose. The pyrolysis behavior in nitrogen atmosphere shows that the weight loss rate of coarse slag is basically zero, and the maximum weight loss rate peak of fine slag is about 470 ℃, which is higher than that of raw coal (440 ℃). The results of pyrolysis under air atmosphere show that the weight loss rate of coarse slag is still very small, but the raw coal and fine slag have obvious weight loss behavior at 400～460 ℃ and 490～560 °C, respectively. Using the Coast-Redfern model, kinetic studies were conducted on the thermal degradation behavior of fine slag. The results indicate that under a nitrogen atmosphere, the pyrolysis intense stage of fine slag (450～500 °C) shows a better fit with a reaction order of 3, with a correlation coefficient R² of 0.99 and an activation energy E of 6.88 kJ/mol. Under air atmosphere, the intense combustion stage of fine slag occurs between 490～560 °C, where a reaction order of n=1 provides a better fit with a correlation coefficient R² of 0.99 and an activation energy E of 24.45 kJ/mol. Based on these findings, coarse slag is not suitable for co-combustion, whereas fine slag can be utilized as a carbon-rich resource for co-combustion.