NOVELTY - A fuel cell catalyst is prepared by preparing precursor solution containing raw material which consists of nanometer diamond, noble metal salt and conductive agent, adding 0.05 mol/L mixed solution of chloroplatinic acid, palladium chloride, ruthenium chloride or de-ionized water to prepared precursor solution of noble metal salt in which volume ratio of chloroplatinic acid and ruthenium chloride is 1:1, adding the solution 10-50 times the volume of glycol solution, adding the mixed solution into a cup, and performing ultrasonic wave oscillation for 30 minutes.    USE - Preparation of fuel cell catalyst for fuel battery.    ADVANTAGE - Fuel cell catalyst prevents electrocatalyst carrier degradation, and has high catalytic activity and high stability.    DETAILED DESCRIPTION - A fuel cell catalyst is prepared by preparing precursor solution containing raw material which consists of nanometer diamond, noble metal salt and conductive agent, adding 0.05 mol/L mixed solution of chloroplatinic acid, palladium chloride, ruthenium chloride or de-ionized water to prepared precursor solution of noble metal salt in which volume ratio of chloroplatinic acid and ruthenium chloride is 1:1, adding the solution 10-50 times the volume of glycol solution, adding the mixed solution into a cup, performing ultrasonic wave oscillation for 30 minutes at 20 kHz vibration frequency and 80 W, uniformly dispersing to form a suspension, putting suspension into the beaker in microwave oven at 2.45 GHz and microwave frequency and 700 W output powder, heating for 60-120 s, taking out the beaker from microwave oven, cooling suspension at room temperature, cleaning with acetone for 3 times, cleaning for 3 times with de-ionized water, drying at room temperature to obtain diamond supported noble metal catalyst powder in which mass ratio of diamond supported noble metal catalyst powder and conductive agent is 4:1, adding water to de-ionized water, uniformly dispersing ultrasonically oscillated de-ionized, and drying to obtain fuel cell catalyst. Nanometer diamond is crushed to 50-100 nm. Noble metal salt contains chlorine molybdenum acid, palladium chloride or ruthenium chloride. Conductive agent contains acetylene black, carbon nanotube or carbon black.