The manufacturing of silicon steel mainly relies on a technology of long process, which has a long process flow, many process nodes and high carbon emissions. In order to actively respond to the policy related with “carbon emission peak and carbon neutrality” and help enterprises achieve energy conservation and emission reduction. A new method was proposed for preparing high-silicon silicon steel thin strips by scrap steel-electric furnace-twin roll casting-solid decarburization. Herein, the effect of temperature and partial pressure ratio of P{}_{\mathrm{C}{\mathrm{O}}_{\mathrm{2}}}/P_CO on the evolution of the solid decarburization oxide scale on 3.5% (mass fraction) silicon steel tripe was studied. During the process carbon in the silicon steel will react with oxygen, so that being removal, while the Si reacts with oxygen forming SiO₂ oxide scale. The results show that for a setting reaction time, with the increasing temperature the oxide scale thickens gradually; for a setting temperature, the oxide scale gradually thickens with the extending decarburization time. Increasing P{}_{\mathrm{C}{\mathrm{O}}_{\mathrm{2}}}/P_CO will accelerate the formation of the surface oxide scale, which will hinder the decarburization reaction in the early stage of decarburization. This study provides an important reference for optimizing the decarburization process and controlling the thickness of the oxide scale.