Abstract: A coal-based porous carbon was prepared through a single activation process. Jincheng smokeless coal was taken as the research object and ferrate (K₂FeO₄) as the activator. Meanwhile, potassium-based substances were served as pore-forming agents and iron-based substances contributed to the catalyzing graphitization. The optimal activation temperature and activator dosage were investigated, and the physicochemical structure of representative samples was analyzed using techniques including Scanning Electron Microscopy(SEM), nitrogen adsorption testing, Raman spectroscopy and X-ray diffraction(XRD). The electrochemical energy storage characteristics were evaluated. On this basis, the effect of N and P element doping on the structure and electrochemical performance of the porous carbon was investigated. The results indicate that, the pore structure of the porous carbon evolves from ultra-micropores to micropores and hierarchical pores, while the carbon microcrystals transition from amorphous to graphitic structures during the one-step chemical activation process with K₂FeO₄. Specifically, with a coal-to-K₂FeO₄ mass ratio of 1:1 and an activation temperature of 900 ℃, the porous carbon attains a specific surface area of 1 220.82 m²/g. At a current density of 0.5 A/g, its capacitance reaches 149.47 F/g, and even at a high current density of 10 A/g, a capacitance retention rate of 77.39% is maintained. The electrochemical performance of the porous carbon is also enhanced to a certain extent after N and P element doping, with a specific capacitance reaching 167.45 F/g, and the capacitance retention rate increased to 87.98%. This porous carbon material, which is characterized by its cost-effectiveness, accessibility, and environmental friendliness, has great potential for industrial applications.