Electrical double layer capacitors (EDLCs) with the merits of high power density and fast charging/discharging have been widely used in the different fields, e.g. green energy and national defense, which is however limited by the unsatisfied energy density. The factors dominating the EDLCs performance mainly include the specific surface area, pore structure (i.e., ion transport channel), conductivity and wettability of the electrode material, the working voltage window and ionic conductivity of the electrolyte. In recent years, mesostructured carbon nanocage have been attracting more and more attention as advanced platform materials for energy storage and conversion, which have a particularly broad application prospect in the field of supercapacitors. Based on the rule of solubility product and the carbothermal reduction method, herein we have developed a new route to regulate the pore size distribution of hierarchical carbon nanocages (hCNCs) and effectively increased the number and size of the channels across the shells of hCNCs. The optimized sample exhibits excellent supercapacitive performances in KOH and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF₄) electrolytes: the specific capacitance of 255 and 220 F•g^－1 at 1 A•g^－1 (50% and 25.7% higher than those of the pristine hCNCs); 179 and 129 F•g^－1 at a high current density of 200 A•g^－1 (68.9% and 33.0% higher than those of the pristine hCNCs); energy density of 12.8 Wh•kg^－1@0.3 kW•kg^－1 and 116 Wh•kg^－1@0.97 kW•kg^－1, respectively. Such excellent electrochemical performances can be attributed to the introduction of small-sized mesopores and the increase in number and size of micropores on the shells of hCNCs, which much increases the specific surface area and benefits the rapid transport of ions through the microchannels on the nanocage shells. This study provides a new thought to develop the advanced supercapacitor electrode materials.