NOVELTY - A method involves preparing a functionalized Vulcan XC-72 (RTM: Carbon black powder). The functionalized carbon black powder is added into chloroplatinic acid and ethylene glycol. The obtained mixture is stirred, reflowed, cooled, centrifuged, washed, dried and ground. The obtained platinum/carbon (Pt/C) catalyst is dispersed and ammonium persulfate of acid aqueous solution is dripped into the mixing solution of Pt/C catalyst and phenylamine. The obtained mixture is reacted under stirring condition, centrifuged, washed, dried and ground to obtain polyaniline decorated Pt/C catalyst.    USE - Method for increasing stability and utilization ratio of a catalyst of a fuel cell that is utilized in an electric automobile, spacecraft and a portable electronic equipment such as camera, notebook computer and electronic toys.    ADVANTAGE - The method enables increasing the stability and utilization ratio of the fuel cell catalyst in a simple and economical manner.    DETAILED DESCRIPTION - A method involves functionalizing a carbon carrier. 1 g of Vulcan XC-72 (RTM: Carbon black powder) is weighed and 150 ml of mixing solution of 30% of hydrogen peroxide and concentrated sulfuric acid are added in a volume ratio of 1:4. The obtained mixture is stirred for 3 hours in an ultrasonic oscillation and diluted by ultra-pure water. The diluted mixture is stewed for 24 hours. The supernatant liquor is filtered, centrifuged, washed and dried. The obtained mixture is ground to obtain a functionalized Vulcan XC-72 (RTM: Carbon black powder). The platinum/carbon (Pt/C) powder is prepared. The functionalized Vulcan XC-72 (RTM: Carbon black powder) and chloroplatinic acid are weighed in a mass ratio of 1:1. Ethylene glycol as a solvent is made to oscillate the mixture in the ultrasonic condition, using 5% of sodium hydroxide solution to adjust a pH value to 1. The obtained mixture is stirred and reflowed for 3 hours at 160 degrees C under nitrogen or argon atmosphere, and the mixture is cooled to room temperature, centrifuged, washed, dried and ground to obtain Pt/C catalyst. Polyaniline decorated Pt/C catalyst is subjected to in-situ synthesis. The Pt/C catalyst and phenylamine are weighed in a mass ratio of 1:0.1-1 and the ammonium persulfate is weighed, where the mole ratio of the phenylamine and the ammonium persulfate is 1:1-1.25. The phenylamine is added in an acid aqueous solution with a pH value of 0-3. The resulting mixture is stirred for 10-30 minutes in an ultrasonic manner. The Pt/C catalyst is dispersed and the ammonium persulfate of acid aqueous solution with a pH value of 0-3 is dripped into the mixing solution of Pt/C catalyst and phenylamine at 0-25 degrees C under stirring condition. The dripping time is controlled within 10-30 minutes, after completing dripping process. The obtained mixture is reacted for 5-24 hours at 0-25 degrees C under stirring condition, centrifuged, washed, dried and ground to obtain polyaniline decorated Pt/C catalyst.