Aiming at the problems such as poor security of heating powder, ablation of residual reagent and difficult cleaning, the carbon dioxide (CO₂) phase transformation system was excited by electrothermal excitation. Considering the physical property distortion of CO₂ in the near critical attached region, a mathematical model of electrothermal excited phase transition of CO₂ was established by using the real gas comparison state equation. Combined with the phase transition experiment of CO₂ under electrothermal excitation, the phase transition characteristics of CO₂ by electrothermal excitation are obtained. The simulation and experimental results show that the electrothermal excitation of CO₂ phase transition is safe, feasible and stable, the calculation deviation of the mathematical model is less than 8.1%. and the reaction time is closely related to the filling coefficient, filling mass and heating power. The simulation results have certain guiding significance for controlling the electrothermal excitation and release process of carbon dioxide phase transition, shortening the excitation time and broadening the application field of CO₂ phase transition energy system such as Mars exploration in the future.