Abstract: CO₂ co-gasification experiments of Zhundong coal （ZDC） with circulating fluidized bed gasification ash （FA: fly ash, BA: bottom ash） and Texaco entrained flow gasification ash （FS: fine slag, CS: coarse slag） were carried out to reveal the influence mechanism of gasification ash on the gasification process of ZDC. Based on thermogravimetric （TG−DTG） technology, the temperature-rise weight-loss profiles （TGA） and weight-loss rate curves （DTG） of the mixed sample of different gasification ash and ZDC were comparatively analyzed. It was found that the addition of gasification ash significantly changed the thermal weight-loss behavior of ZDC. By introducing the reactivity index R_0.5 and the specific reactivity index, the CO₂ gasification reactivity of each mixed sample after adding different gasification ash was quantitatively evaluated. Compared with ZDC, the R_0.5 value of all the mixed sample increased more or less. In particular, the addition of FA was particularly prominent, with its R_0.5 as high as 0.075, demonstrating that the addition of gasification ash presents significant promoting effect on the gasification reactivity of ZDC. And the mechanisms might be concluded as improving the heat and mass transfer process, providing catalytic active sites, and changing the reaction path. The thermal weight-loss profiles were fitted and analyzed using Coast - Redfern kinetic model, and the linear relationship between −ln（1−x）/T² and 1/T was established. Results showed that the activation energy of CO₂ gasification reaction of each mixed sample is as follows: 160.29 kJ/mol for ZDC, 248.89 kJ/mol for ZDC+FA, 202.59 kJ/mol for ZDC+BA, 188.13 kJ/mol for ZDC+CS, and 205.33 kJ/mol for ZDC+FS. That is, in comparison, the addition of CS was more conducive to the gasification reaction process of ZDC.