This paper describes a simulation method of a combustion furnace with the partial equilibrium method. In this research, turbulent mixture of chemical species with air is considerd first by the eddy dissipation model, and then, species for combustion is estimated by Arrhenius rate. Finally, the products are calculated with the mixed air for combustion by the chemical equilibrium method. The predicted results are in close agreement with the experiment data but benzene and naphthalene can not be calculated. The cause is the boundary condition is different from the experimet and comparison between the calculation and the experiment is needed.