NOVELTY - A graphene-coated metal nanoparticle catalyst preparing method involves taking carbon carrier, iron source and nitrogen source and mixed with water and ethyl alcohol. The mixed solution is stirred at 25-50 degrees C for 1-3 hours and mixed with ethylene diamine tetraacetic salt and methyl alcohol at 120-180 degrees C for 3-24 hours. The mixed solution is washed with water until neutral, filtered and dried at 50-100 degrees C fro 5 hours to obtain Fe-N-CNTEDTA composite material. The obtained material is heated under inert gas at 500-900 degrees C for 1-5 hours to obtain grapheme-coated metal nanoparticle catalyst.    USE - Method for preparing grapheme-coated metal nanoparticle catalyst for use asproton exchange membrane fuel battery, alkaline anion-exchange membrane ORR electric or fuel cell cathode metal-air battery catalyst (claimed).    ADVANTAGE - The method enables preparing grapheme-coated metal nanoparticle catalyst with simple operation, low preparation cost, high activity and high stability.    DETAILED DESCRIPTION - A graphene-coated metal nanoparticle catalyst preparing method involves taking 3.33-16.67 g L-1 carbon carrier, 0.003-0.006 mol L-1 iron source and 0.013-0.039 mol L-1 nitrogen source and mixed with water and ethyl alcohol at volume ratio of 1: 1-3: 1, where the carbon carrier comprising carbon nano tube, coal black, graphene oxide and graphene series, the nitrogen source comprises dicyandiamide, melamine, ammonia and water and the iron source comprises ferric chloride, ferrous sulfate, and ferric ammonium. The mixed solution is stirred at 25-50 degrees C for 1-3 hours and mixed with ethylene diamine tetraacetic salt and 5.2-8.2 mol L-1 methyl alcohol at 120-180 degrees C for 3-24 hours. The mixed solution is washed with water until neutral, filtered and dried at 50-100 degrees C for 5 hours to obtain Fe-N-CNTEDTA composite material. The obtained material is heated under inert gas at 500-900 degrees C for 1-5 hours to obtain grapheme-coated metal nanoparticle catalyst.