Against the backdrop of the low-carbon energy transition, catalytic gasification is a crucial approach for achieving a gentle and efficient conversion of coal, as well as reducing energy consumption and carbon emissions. elucidating the evolution of coal char gasification reactivity and the mechanisms governing its kinetic regulationis ofsignificant scientific andengineeringvalue forthehighly efficientandcleanutilization ofcoal.In this study,anthracite (YN)andbituminouscoal(TJ) wereselectedastheresearchobjects.Tocloselysimulatethe real industrial environment, the coal char was prepared by pyrolysis at a high temperature of 1500 °C in a tube furnace. CaO-loaded coal chars were prepared using direct addition and impregnation methods. Variable kinetic parameters were obtained through isothermal thermogravimetric experiments and the General SurfaceActivation Function Model (GSAFM), while structural evolution was characterized using FSEM and Raman spectroscopy. The results demonstrate that the catalytic effect of the impregnation method is superior to the physical mixing of the direct addition method, it is pointed out that the close contact between CaO and the coal char matrix is a crucial prerequisite for the catalytic effect to take place. GSAFM can well describe the catalytic gasification behaviorofcoalcharintheentireconversionrange.CaOprimarilyenhancescharreactivitybyreducingthemean activation energy; however, the stage-dependent mechanism based on variable kinetics is significantly regulated by the reaction atmosphere. Under an O2 atmosphere, the early reaction stage is dominated by the variable activation energy (EX), while the later stage shifts to being controlled by the variable pre-exponential factor (AX). Under a CO2 atmosphere, AX governs the initial reactivity difference, the decrease in EX plays the primary role in the middle stage, andthe influence of AX strengthensagain in the later stage. Undera H2O atmosphere, the initial AX is higher, and EX continuously decreases throughout the middle and later stages, ensuring the reaction rate of the catalyzed char remains consistently higher. Furthermore, FSEM reveals that CaO significantly intensifies the surface reconstruction of coal char. Raman spectroscopy indicates a decrease in the ID1/IG ratio and an increased degree of graphitization in the catalyzed char; nevertheless, the reaction rate still significantly improves. This suggests that the reaction enhancement primarily originates from the reconstruction of active sites and the alteration of surface reaction pathways. This study clarifies the stage-dependent kinetic mechanism of CaO catalysis,providingatheoreticalbasisforthedesignandmodelingofhighlyefficientcoalgasificationcatalysts.