Abstract: To achieve synergistic regulation of morphology-interface-composition in electrospun nitrogen-doped carbon nanofibers (CNFs) through polydopamine, this study employed dopamine (DA) and polyacrylonitrile (PAN) as raw materials, combined with electrospinning technology, and successfully prepared flexible self-supporting nitrogen-doped carbon nanofibers via an in-situ self-polymerization-pre-oxidation-carbonization process. The experiments investigated the influence of spinning parameters and carbonization conditions on the material's structure and electrochemical performance. Results demonstrated that factors such as spinning solution concentration and collector rotation speed significantly affected the diameter, alignment, pore structure, mechanical properties, and conductivity of CNFs. By incorporating 10% dopamine and adopting a 280℃ pre-oxidation pretreatment, the flexibility and strength of the fibers were preserved. Carbonization at 700℃ established a nitrogen-doped system, creating more efficient charge transport pathways while endowing the fibers with a hierarchical porous structure comprising surface micropores and interwoven macropores, which facilitated ion diffusion and energy storage. Under optimized conditions, the fibers exhibited an average diameter of 340 nm, forming a three-dimensional layered network with abundant surface micropores. The conductivity reached 0.297 S·cm⁻¹, and the specific capacitance achieved 228 F·g⁻¹ at a current density of 1 A·g⁻¹, demonstrating excellent rate capability and cycling stability. This work provides valuable insights for developing high-performance supercapacitor electrodes by constructing ordered three-dimensional hierarchical porous nanomaterials without pore-forming agents.