The invention belongs to the field of catalysis and oxidization, and particularly discloses a method for preparing 1, 2-diketone by catalyzing and oxidizing alkynes. The method comprises the following steps: taking alkynes R1-C-C-R2 (acetylenic link exists between C and C) as a reaction substrate, taking one of TBHP, m-chloroperoxybenzoic acid and p-benzoquinone as a oxidant, taking one of dichloro (p-cymene) ruthenium (II) dimer, tri (triphenylphosphine) ruthenous chloride, ruthenium acetate, ruthenium dichlorophenyl (II) dimer, ruthenium trichloride, BINAP ruthenous chloride, dodecacarbonyltriruthenium and tricarbonyldichlororuthenium (II) dimer as a catalyst, taking one of iodine, iodine chloride, iodine bromide, potassium iodide, tetrabutyl ammonium iodide and potassium bromide as a cocatalyst, and taking 1, 4-dioxane as a solvent to react under 40 DEG C to 100 DEG C for 4 to 24 h to prepare the 1, 2-diketone. The method is economic, environmental-friendly and mild.