The invention discloses a 
nitrogen doped porous 
active carbon material, which is prepared by burning a carbon precursor prepared from sago 
cycas, a 
nitrogen source, and an alkaline inorganic substance. The specific surface of the material is in a range of 1136 to 2628 m<2> / g, and the average aperture is in a range of 1.17 to 2.11 nm. The preparation method comprises the following steps: step one, washing the leaves of sago 
cycas by water, 
drying the leaves, 
grinding the leaves, and burning the leaves to obtain a carbon precursor; step two, mixing the carbon precursor, the 
nitrogen source, and the alkaline inorganic substance, soaking, 
drying, burning, and carrying out activation to obtain a 
nitrogen doped porous 
active carbon material; and step three, soaking the 
nitrogen doped porous 
active carbon material in an acid solution, washing, filtering, 
drying, and 
grinding to obtain the final 
nitrogen doped porous active carbon material. When the material is used as the 
electrode material of a super 
capacitor, and if the 
current density is 1 A g<-1>, the specific 
capacitance is in a range of 266 to 351 F g<-1>. Leaves of sago 
cycas are taken as the raw materials, the application range is enlarged; and the material has a wide application prospect in the fields of porous materials and super 
capacitor.