NOVELTY - Preparing catalytic agent comprises weighing Vulcan XC-72 (RTM: Carbon powder), adding solution of hydrogen peroxide and concentrated sulfuric acid, ultrasonically oscillating the solution and then diluting by super-pure water and standing, filtering clear liquid, centrifuging the filtered solution, carrying out cleaning, drying and grinding, and preparing nickel-iron/carbon nanoparticles by mixing nickel acetylacetone, iron acetylacetone, oleic acid, sodium hydroxide, sodium borohydride and Vulcan XC-72 (RTM: Carbon powder) and then slowly adding the sodium borohydride.    USE - The catalytic agent is useful for proton exchange membrane fuel cell electrolyte (claimed) for electric automobiles, spacecrafts, portable electronic equipment including cameras, notebook computers or electronic toys.    ADVANTAGE - The method allows simple, rapid and economical preparation of the catalytic agent with small size and high dispersion.    DETAILED DESCRIPTION - Preparing catalytic agent comprises (a) weighing 1 g of Vulcan XC-72 (RTM: Carbon powder), adding 30 wt.% of solution hydrogen peroxide and concentrated sulfuric acid according to volume ratio of 1:4, ultrasonically oscillating the solution for 3 hours and then diluting using super-pure water and standing for 24 hours, filtering clear liquid, centrifuging the filtered solution for several times, carrying out cleaning, drying and grinding to obtain functionalized Vulcan XC-72 (RTM: Carbon powder), and (b) preparing nickel-iron/carbon nanoparticles by mixing nickel acetylacetone, iron acetylacetone, oleic acid, sodium hydroxide, sodium borohydride and functionalized Vulcan XC-72 (RTM: Carbon powder) according to weight ratio of 1:1-2:0.01-0.03: 0.01-0.02:5-10:1-2.5, adding nickel acetylacetone, iron acetylacetone, oleic acid and sodium hydroxide into 50-100 ml or 250 ml of three-necked bottle under nitrogen atmosphere, raising temperature to 110-130 degrees C or 140-160 degrees C for 1.5-2.5 hours, slowly adding the sodium borohydride to the mixed solution, controlling the temperature to 10-30 degrees C/minutes or 140-160 degrees C, continuously reacting the mixture for 2-40 minutes and then cooling the reaction liquid to 60-80 degrees C, stirring and absorbing the mixture for 12-36 hours, centrifuging obtained product by absolute ethyl alcohol to wash for 3-6 hours and then vacuum drying 60-80 degrees C for 6-24 hours, preparing platinum/carbon catalyst by adding nickel-iron/carbon nanoparticles and molybdenum salt according to mass ratio of 1:0.4-0.6, dispersing nickel-iron/carbon nanoparticles product in 15-30 mmole/l of ethylene glycol, stirring and raising the temperature to 60-80 degrees C, gradually adding dissolved mixture in ethylene glycol, dripping in the molybdenum salt at 60-80 degrees C for 1-60 minutes, reacting the mixture for 12-48 hours, centrifugally washing the product for 3-6 hours with absolute ethyl alcohol and vacuum drying at 60-80 degrees C for 6-24 hours.