NOVELTY - Preparation of nitrogen-doped carbon nanotube supported cobalt-based electrocatalytic material involves taking terephthalic acid, trimesic acid or 4,4'-dicarboxy biphenyl as organic ligand, melamine or 2,2'-bipyridyl as nitrogen-containing organic compound and cobalt nitrate, cobalt sulfate, cobalt chloride, cobalt acetylacetonate or cobalt acetate tetrahydrate as cobalt salt at molar ratio of 0.5-5:0.5-5:1, grinding, adding 10-15 times mixed solvent comprising N,N-dimethylformamide and ethanol at volume ratio of 1-10:1, heating to 100-140 degrees C, filtering, washing precipitate and oven drying.    USE - Method for preparing nitrogen-doped carbon nanotube supported cobalt-based electrocatalytic material used as fuel cell cathode catalyst (claimed).    ADVANTAGE - The electrocatalytic material has 0.85-0.88 V initial potential, 0.66-0.69 V half-wave potential, - 3.74 to - 3.93 mA/cm2 limiting current density and 3.69-3.90 electron transfer number, has stability test 24000 seconds higher than palladium on carbon catalyst with 20% palladium, and can maintain catalytic properties at 84-88%.    DETAILED DESCRIPTION - Preparation of nitrogen-doped carbon nanotube supported cobalt-based electrocatalytic material comprises taking terephthalic acid, trimesic acid or 4,4'-dicarboxy biphenyl as organic ligand, melamine or 2,2'-bipyridyl as nitrogen-containing organic compound and cobalt nitrate, cobalt sulfate, cobalt chloride, cobalt acetylacetonate or cobalt acetate tetrahydrate as cobalt salt at molar ratio of 0.5-5:0.5-5:1, grinding, adding 10-15 times mixed solvent comprising N,N-dimethylformamide and ethanol at volume ratio of 1-10:1, heating to 100-140 degrees C with 1-20 degrees C/minute heating rate in PTFE reactor, insulating for 6-36 hours, cooling, filtering, washing precipitate, oven drying at 40-80 degrees C to obtain cobalt-containing metal-organic framework material (Co-MOF) precursor, heating to 600-1000 degrees C with 1-10 degrees C/minute heating rate in the presence of nitrogen or argon in tube furnace, insulating for 3-9 hours, etching with 10% nitric acid for 0.5-3 hours, centrifuging, washing and drying at 40-80 degrees C.