Porous carbon nanospheres (PCNSs) with an ultrahigh specific surface were successfully prepared by carbonizing monodisperse polypyrrole nanospheres and subsequent active treatment by KOH. A hierarchical composite composed of PCNSs and polyaniline (PANI) nanorods arrays (PCNSs/PANI) were further synthesized via in situ polymerization of aniline on PCNSs. The PCNSs displayed an ultrahigh specific surface area (2817.7 m² g⁻¹), abundant mesoporous structures and high specific capacitance (320 F g⁻¹). They delivered a capacitance retention of 100% after 1000 cycles at a current density of 5 A g⁻¹. When composed with PANI nanorods, the specific capacitance of PCNSs/PANI reached up to 584 and 407 F g⁻¹ at 0.2 and 5 A g⁻¹, respectively. The superior performance of PCNSs/PANI was attributed to the hierarchical structures and synergistic effect between PANI and PCNSs. The unique structures and outstanding properties of these materials make them excellent candidates for high-performance supercapacitors.