NOVELTY - Carbon-carried ultra-low platinum catalytic electrode is prepared by indirect electrodeposition involving preparing micropore layer, porous carbon electrode, and high-dispersion size-controllable M/PCE electrode using four-step electrodeposition method. The first electrodeposition is carried out at 0.1-1 A/dm2 for 50-150 seconds. The second electrodeposition is carried out at 5-30 A/dm2 for 1-5 seconds. The third electrodeposition is carried out at 0.1-1 A/dm2 for 20-120 seconds. The fourth electrodeposition is carried out at 2-20 A/dm2 for 2-8 seconds.    USE - Method for preparing carbon-carried ultra-low platinum catalytic electrode (claimed) for replacing platinum/carbon catalyst used for fuel cell.    ADVANTAGE - The method has simple process with low cost. The method provides carbon-carried ultra-low platinum catalyzing electrode with low platinum loading, high catalytic performance, good dispersion of platinum nanometer particles, and controllable size.    DETAILED DESCRIPTION - Preparing carbon-carried ultra-low platinum catalytic electrode comprises indirect electrodeposition. The indirect electrodeposition comprises preparing micropore layer, preparing porous carbon electrode, preparing high-dispersion size-controllable M/PCE electrode using four step electrodeposition method, and preparing carbon-carried ultra-low platinum catalytic electrode. The preparing of micropore layer comprises soaking a carbon paper in ethanol water, oscillating carbon paper for 30 minutes under ultrasonic wave, soaking carbon paper in a 30% PTFE emulsion for 30 minutes, roasting carbon paper in a muffle furnace at 340 degrees C for 40 minutes, obtaining a hydrophobic diffusion layer, weighing PTFE and Vulcan XC-72(RTM: carbon powder) at mass ratio of 1:1, oscillating the PTFE and Vulcan XC-72(RTM: carbon powder) using ethanol as solvent under ultrasonic wave until the mixture is uniform, painting the mixture on hydrophobic diffusion layer, roasting the painted mixture in muffle furnace at 340 degrees C for 45 minutes, and obtaining micropore layer. The preparing of porous carbon electrode comprises weighing 0.5 % perfluorosulfonic resin, and Vulcan XC-72(RTM: carbon powder) at mass ratio of 1:30, oscillating the mixture using ethanol as a solvent under ultrasonic wave, painting several times the mixture on the micropore layer, drying the painted micropore layer at 140 degrees C, and obtaining a porous carbon electrode (PCE) spliced by perfluoro-sulfonic resin. The preparing of high-dispersion size-controllable M/PCE electrode comprises using a two-electrode system. The two electrode system comprises porous carbon electrode spliced by perfluoro-sulfonic resin as a cathode, and metal as an anode. The electrolyte is an acidic aqueous solution containing a water-soluble salt of metal (0.001-1 mol/L). The electrodeposition temperature is 10-50 degrees C. The preparing of high-dispersion size-controllable M/PCE electrode comprises using four-step electrodeposition at different parameters. The first step electrodeposition parameter is at 0.1-1 A/dm2 for 50-150 seconds. The second step electrodeposition parameter is at 5-30 A/dm2 for 1-5 seconds. The third step electrodeposition parameter is at 0.1-1 A/dm2 for 20-120 seconds. The fourth step electrodeposition parameter is at 2-20 A/dm2 for 2-8 seconds. The preparing of a carbon-carried ultra-low platinum catalyze electrode comprises cleaning the high-dispersion size-controllable M/PCE electrode with ultra-pure water, soaking the electrode in a platinum salt aqueous solution protected by nitrogen for displacement, controlling pH value of the platinum salt aqueous solution (0.1-30 g/L) at pH 0-8, and obtaining a carbon-carried ultra-low platinum catalytic electrode after 0.5-3 hours of displacement.