The experimental study of the magnetic field effect on the swirling flame flow formation by co-firing the wood fuel with propane is carried out with the aim to estimate the magnetic field effect on the flame dynamics, processes of heat/mass transfer and the formation of the flame composition. The results have shown that the magnetic force, acting on the flame flow enhances the mass transfer of paramagnetic oxygen in a field direction- to the surface of burning wood fuel by enhancing recirculation with the reverse axial flow formation and more intensive mixing of the flame compounds. The field-enhanced mixing of the flame compounds and combustion of the volatiles promotes a radial expansion of the flame reaction zone, completing burnout of the volatiles and increasing the total amount of produced heat. In fact, the field-enhanced burnout of the volatiles so promotes a slight increase of the mass fraction of NOx (≈5%) - up to 70 ppm (≈150 mg/m3) that is quite acceptable value for the wood fuel burnout.