The invention discloses a method for preparing a hierarchical pore carbonic oxide microsphere material. The method comprises the following steps: A, impregnating PU foam with a PAA solution, and drying for 6-20 hours at 50-90 DEG C in vacuum; B, heating the PU foam after impregnating and drying in an inert gas atmosphere, namely heating for 0.5-3 hours at 80-120 DEG C, increasing the temperature to 170-230 DEG C and heating for 0.5-3 hours, and increasing the temperature to 270-330 DEG C and heating for 0.5-3 hours; and C, roasting for 1-6 hours at 500-800 DEG C in the inert gas atmosphere after the heating treatment in the step B is completed, and cooling to room temperature. The method is simple, has low cost and short reaction time, and is suitable for industrial production; and the prepared carbonic oxide microsphere material has an ideal flower-like spherical shape, a micropore-mesopore-macropore hierarchical porous structure, a large specific surface area, high nitrogen content and excellent electrochemical performance, and has huge application prospects in the field of super-capacitors.