<p>An innovative environmentally friendly biomass co-carbonization technology has been developed to achieve efficient preparation of sintered carbon-based synfuels through synergistic thermal conversion technology. The experimental results indicate that a carbon-based synfuel with a solid yield of 54.30%, a bulk density of 380&#xa0;kg∙m⁻³, and a calorific value of 33.2&#xa0;MJ·kg⁻¹ was successfully prepared by the co-carbonization technology at a carbonization temperature of 600&#xa0;°C for a carbonization time of 60&#xa0;min with a CaO/Fe₂O₃ additive loading amount of 6 wt.% and a CaO: Fe₂O₃ ratio of 50:50 (wt.%). In the collaborative pyrolysis process of sawdust and bituminous coal, the addition of CaO/Fe₂O₃ can increase the activation energy from 43.6&#xa0;kJ·mol⁻¹ and 10.3&#xa0;kJ·mol⁻¹ to 76&#xa0;kJ·mol⁻³ and 19&#xa0;kJ·mol⁻¹ during the rapid and slow pyrolysis stages, respectively. CaO and Fe₂O₃ facilitate an effective transition between the low-temperature pyrolysis and high-temperature carbonization stages, ultimately achieving a synergistic improvement in both the distribution and quality of the pyrolysis products. In the combustion process of a carbon-based synfuel, the addition of CaO/Fe₂O₃ can lower the ignition point and the temperature at which the maximum reaction rate occurs during the combustion of the composite fuel and decrease the activation energy of the combustion reaction.</p> Graphical Abstract <p></p>