The invention discloses a p-phenyl dialkynol mono-oxidation product and a preparation method thereof and belongs to the technical field of chemical engineering. A structural formula of the p-phenyl dialkynol mono-oxidation product is shown in the description. The preparation method comprises the specific steps that every 0.6 g of p-phenyl dialkynol is added to a 100 ml single-neck flask, 30 ml of diethyl ether is added, then 6.6 g of active manganese dioxide is added, mixing reaction is performed at room temperature for 4 hours, then suction filter is performed, filter residues are washed with diethyl ether, a small amount of 100-200-mesh silica gel is added to filtrate, and column chromatography separation is performed by using 200-300-mesh silica gel after spin drying of the solvent. Oxidation separation is conducted on 1,4-phenyl dialkynol by using the active manganese dioxide to obtain the mono-oxidation product 4-propiolyl benzene alkynol, and a simple and convenient method for synthesizing the 4-propiolyl benzene alkynol is provided.