Carbonaceous materials attract various attentions as supercapacitor electrode due to their low cost, high stability, and large specific surface area. However, the enhancement of energy storage for carbon electrode is limited by the difficulty in constructing the carbon surface well-compatible for ions and electrons transfer, and by the unclear mechanism. Herein, we develop an oxygen-modulated porous activation strategy (OMPA), by which the transport of electrons and ions can be simultaneously accelerated at the as-produced carbon electrode surface. The key to OMPA lies in the preoxidation of carbon nanospheres (CN), followed by activation with potassium hydroxide. The surface oxygen on oxygen-functionalized CN (OCN) can enable the activated OCN (AOCN) with optimized hierarchical porosities dominated by K+-matched micropore of 0.66 nm, and with an electron transfer interaction with the reserved oxygen. These prominent structures effectively arouse the electrons and ions transfer in the AOCN, as revealed by kinetics analyses and theory calculation. Thu, the AOCN as a supercapacitor electrode delivers a specific capacitance of 282 F g−1 at 0.5 A g−1, maintaining 67% after current density magnifying by 60 times. This work supplies the guidance to rationally design advanced carbon materials as supercapacitors electrode via precisely-tailoring surface characteristic.