Abstract: Coal has unique advantages as a precursor for producing porous carbon electrode materials for supercapacitors due to its high carbon content, condensed aromatic structure, and significant economic benefits. By solvent extraction of coking coal from Shanxi, coal based heavy component （HC） was obtained as carbonaceous precursor, and KOH was used as an activator to prepare porous carbon materials （AHC）. Then, ammonia water was used for hydrothermal modification at certain conditions to obtain a nitrogen-doped porous carbon with high rate performance and high cycling stability. The influence of different amounts of ammonia water addition on the microstructure, pore structure, surface chemical properties, and electrochemical performance of porous carbons was studied through characterization analyses such as SEM, FTIR, XPS, Raman, and N₂ adsorption. The results showed that the surface morphology and pore structure of the modified porous carbons were improved. When the ammonia addition was 8 mL, the resulting modified porous carbon AHC−N8 exhibited a distinct wormlike nano crack pore nitrogen content from 0.66% （without modification） to 2.83%. The porous carbon electrode material has a structure, with an increased proportion of mesopores and a surface specific capacitance of 351.3 F/g and a rate performance of 82% at a current density of 1 A/g, which is greatly improved compared to AHC （63.5%）. After 10000 cycles of charging and discharging at 10 A/g, the specific capacitance retention rate increased from 91.4% to 95.6%. The high specific surface area, suitable micro/mesoporous distribution, and high surface doping of pyridine nitrogen and pyrrole nitrogen contribute to the outstanding electrochemical performance of AHC−N8.