NOVELTY - A molybdenum source, other metal sources and aliphatic alcohol reducing agent are added simultaneously into nonpolar solution. To the solution, oleic acid and oleylamine are added. The obtained solution is stirred under vacuum and purged with nitrogen to remove dissolved oxygen in the system. The solution is heated under vacuum to dissolve all the reactants and water is removed to obtain molybdenum alloy nanoparticles. The obtained molybdenum alloy nanoparticles is added to ethanol anti-precipitate, centrifuged and washed to obtain oil-soluble binary molybdenum alloy nanoparticles.    USE - Preparation of platinum alloy nanoparticles used in fuel cells.    ADVANTAGE - The platinum alloy nanoparticles having controllable shape and crystal surface, and excellent electrocatalysis property is prepared efficiently by simple process with good reproducibility, without using secondary injection.    DETAILED DESCRIPTION - A molybdenum source, other metal sources and aliphatic alcohol reducing agent are added simultaneously into nonpolar solution. Then, to the solution oleic acid and oleylamine are added with volume ratio of 1-10:10-1 as ligand. The concentration of molybdenum metal source in the nonpolar solution is 10-20 mmol/L. The concentration of the oleic acid and oleylamine ligands is 1-20 vol.%. The molar ratio of molybdenum source and other metal source is 1-1:1-3. The molar amount of aliphatic alcohol reducing agent is 10-20 times with respect to molybdenum source. The obtained solution is stirred under vacuum, purged with nitrogen, repeatedly vacuumized and introduced nitrogen for 2-4 times, for every 5-15 minutes to remove dissolved oxygen in the system. Then, the solution is heated at 50-100 under vacuum, kept for 20-60 minutes to dissolve all the reactants completely, water is removed under protection of nitrogen and maintained at 180-250 degrees C for O.5-1.5 hours to obtain molybdenum alloy nanoparticles. The obtained molybdenum alloy nanoparticles is added to ethanol anti-precipitate, centrifuged and dissolved in chloroform to wash. Centrifugation and washing are repeated for 3-4 times, to remove residual ligand and by-product, and to obtain oil-soluble binary molybdenum alloy nanoparticles.