With the aim to provide control of biomass thermal decomposition and combustion of volatiles, the external electric field effect on the wood biomass gasification/combustion characteristics during biomass thermo-chemical conversion at different stages of the swirling flame formation and heat energy production was experimentally studied.The DC electric field effect on combustion dynamics was studied using a single electrode configuration by inserting an electrode through the biomass layer to the base of flame reaction zone. An experimental study of the electric field effect on the development of two-stage process of biomass thermal decomposition and combustion of volatiles was performed by providing complex measurements of field-induced variations of biomass weight loss determining the formation of the axial flow of volatiles, kinetics of ignition and combustion of volatiles and formation of swirling flow structure. Results of experimental study and analysis of the electric field effect on combustion dynamics have shown that the field-enhanced thermal decomposition and the swirl-induced upstream flow formation with swirl-enhanced mixing of flame compounds are the primary factors determining the above mentioned effect on the combustion dynamics and heat energy production, promoting a faster ignition and a more complete combustion of volatiles. In addition, the field-induced interrelated processes of radial heat and mass transfer (ion wind effect) in the flame reaction zone can be used to control the formation of the swirling flow structure and heat energy production.