The invention belongs to the field of biomass carbon material preparation and particularly discloses a process using date pits to prepare nitrogen-doped porous carbon material and a preparation method of a super-capacitor electrode. The process includes the steps of firstly, preprocessing the date pits; secondly, preparing nitrogen-doped carbon material; thirdly, preparing the nitrogen-doped porous carbon material. The process is characterized in that the date pits are used as the carbon source and mixed with ammonia gas and steam in inert protecting gas, the nitrogen doping reaction is performed during the carbonization process, activated perforation is performed under the effect of activating agent, and the nitrogen-doped porous carbon material with high specific surface area and pore volume is prepared. The preparation method is simple, low in cost, high in preparation efficiency and energy saving. Experiments show that the super-capacitor electrode prepared by the nitrogen-doped porous carbon material has high specific capacitance, ideal pseudo-capacitance and high circulation stability, the performance of the super-capacitor electrode is better than the performance of commercial activated-carbon super-capacitors, and the performance of the nitrogen-doped porous carbon material is better than that of most nitrogen-doped porous carbon materials.