The utility model relates to a conical porous medium combustor applicable to biomass gasification gas, which is provided with diverging pipes. Porous media with a catalytic effect are filled in the diverging pipes, a heater is wrapped on the outside of each diverging pipe, the integral diverging pipes are buried in a heat-insulation layer, an expansion chamber is mounted at inlets of the diverging pipes, a backfire preventive part and a flow equalizing plate are mounted in the expansion chamber, and a premixing pipe is connected to an inlet of the expansion chamber. By the aid of the conical porous medium combustor, unstable combustion such as inclined flame and the like can be prevented, flame can be effectively prevented from being blown out of the combustor, and the power and the working range of the combustor are increased to adapt to change of load and working conditions of the combustor. In addition, the conical porous medium combustor has a self gas flow regulating function, flameout due to excessively small load of the parallel diverging pipes or excessively large load is prevented, super-adiabatic combustion of the biomass gasification gas in the combustor can be realized, lean inflammable limit of fuel is greatly expanded, and the fuel with an extremely low heat value can be combusted stably. Besides, a flame region is widened, pyrolytic combustion of tar is accelerated beneficially, and combustion efficiency is enhanced.