TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The electrocatalyst has wall thickness of 0.1-2 nm, hollow sphere particle diameter of 10-30 nm, pore size distribution on the wall surface of pores is 0.2-5 nm, and the pore volume on the wall, is 10-50%. The the carbon carrier is activated carbon Vulcan XC-72 (RTM: Conductive carbon black), KB300, KB600 or BP2000. Preferred Method: The method comprise carrying out precipitation process of low-boiling polar solvent to lift the protective effect of nano-alloy catalyst of protective agent, where the low-boiling polar solvent is isopropanol, ethanol or acetone, promoting settlement processing temperature is room temperature at 60 degrees C and the processing time is 2-8 hours. The method comprises (a) preparing a second aqueous solution of metal precursors by uniformly dissolving second metal precursor in deionized water at room temperature, where second metal ion concentration in the aqueous solution is 1-20 mM, and the optimum concentration is 3-10 mM, and second metal precursor is halides, nitrates, acetates or water-soluble complex salts; (b) preparing a second colloidal solution of metal nano-seed by adding aqueous solution of complexing agent at room temperature, adding etching agent into a protective agent, and completely dissolving by adding a reducing agent, controlling the temperature of second metal precursor added with aqueous solution, carrying out reduction reaction of second metal ions for 1-5 hours, to obtain a colloidal solution of metal nano second seed, where the molar ratio of protective agent and the second metal ion is 0.5:1-5:1, the optimum molar ratio is 1:1-3:1, the molar ratio of the complexing agent and the second metal element is 0.5:1-5:1, the optimum molar ratio is 1:1-3:1, and the molar ratio of the complexing agent and etching agent is 1:1-1:10, and the reaction is controlled at room temperature of 110 degrees C, and then determining the molar ratio of the reducing agent and the transition metal ion stoichiometry of the reaction according to the ratio, where the reducing agent is an organic acid having a weak reductive, including ascorbic acid, citric acid or oxalic acid; (c) preparing a porous wall, a colloidal solution of nano-hollow seed by placing platinum-precursor solution at room temperature of 110 degrees C, and adding into colloidal solution of metal nano second seed to carry out displacement reaction for 5-40 hours, preferably 20-25 hours, to obtain porous wall, colloidal solution of nano hollow seeds, where the platinum-precursor is hexachloroplatinic acid, platinum(IV) chloride, potassium hexachloroplatinate, sodium hexachloroplatinate or potassium tetrachloroplatinate, and aqueous solution concentration of platinum elements is 1-20 mM, and the optimum concentration is 3-10 mM; (d) carrying out pro-precipitation of platinum-based catalyst nano-particles by uniformly dispersed purified treated carbon support in colloidal solution of nano seed, uniformly stirring PtxMy nanoparticles supported on the carbon support surface for 4-12 hours, and then carrying out purification of the carbon support using an aqueous solution of a non-oxidizing acid to remove impurities of carbon carrier processed at 60-80 degrees C for 2-8 hours, under optimum processing time of 3-5 hours, where the non-oxidizing acid is hydrochloric acid or nitric acid concentration of 0.1-2 M, and then adding low-boiling polar organic solvent, lifting the protection agents on protective effect of nano particles, uniformly promoting adsorption of nano-particles on the surface of the carbon support, and carrying out rapid precipitation, where the molar ratio of the polar organic solvent and the protecting agent is 300:1-100:1, and the optimum molar ratio is 200:1-150:1; and (e) treating supported platinum-based catalyst nanoparticles, carrying out centrifugation or filtration, adding deionized water, and drying, to obtain the final product.