Circulating fluidized bed (CFB) has been widely used for the conversion of low-grade fuels such as gangue and sludge. In re⁃cent years, with the changes in the applications and requirements, extensive adaptive modifications have been made to the CFB. Accuratesimulation and prediction of the combustion performance inside the fluidized bed can provide fundamental support for these modifications.A fluidized bed model based on thermodynamics and kinetics was constructed to address the complexity of current fluidized bed models andthe difficulty of accurately predicting multiple parameters. The influence of fuel variation on the oxygen demand, as well as the variation ofvoid fraction and temperature with bed height were calculated. By constructing the thermodynamic model, the theoretical oxygen demandsfor four types of coal gangue with carbon contents of 74.05%, 17.71%, 24.27% and 34.01% were predicted, with theoretical oxygen de⁃mand of 15.17, 4.00, 4.47 and 6.20 kg/ h, respectively. The calculated results were related to fuel type and theoretical oxygen demand,which can assist in the design of parameters such as fan power and air volume. Furthermore, by embedding 10 RCSTR dynamic modules inseries into the kinetic model, the key parameters, including void fraction, temperature, and gas distribution, for different bed layerswere calculated,with the single-point parameter error of less than 15%. The classification and prediction of different types of static indica⁃tors can be achieved by the establishment of a multi process model fusion method, providing theoretical basis and design references for reg⁃ulating parameters such as fluidized bed air flow rate and primary-secondary air inlet positions during fuel transformation.