Abstract: While burning solid fuels, like biomass, coal andwaste, wall-burning will occur to a certain extent. With the coal-fired liquid-bath combustor as an example, the mechanism of coaldeposition, movement and combustion on the molten surface are discussed.In order to overcome the limitation of existing simulation methods for burningcharacteristics in the liquid-bath combustor, this paper proposes awall-burning model considering the slag flow condition and gives a totalcomputational frame work. From the comparison of simulation results with severalother methods, their difference and properties are analyzed, whichcan provide a guidance for the simulation of liquid-bathcombustor and guidance for the simulation of biomass or wastecombustion.