The invention discloses a method for preparing 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Iso-butyryl chloride used as a raw material is stirred evenly in ether solvent, triethylamine is added, reflux reaction is carried out for 13-16h, diluted hydrochloric acid is used for washing, pressure is reduced to remove solvent to obtain intermediate 2,2,4,4-tetramethyl-1,3-cyclobutanedione, the intermediate is dissolved in mixed solvent of methyl alcohol and water, NaOH is used for regulating pH value to be alkaline, quantitative NaBH4 is added in batches under an ice-bath condition, the reaction is performed for 3-5h at normal temperature, diluted hydrochloric acid is used for quenching, solvent is removed, absolute ethyl alcohol is used for extraction, after ethyl alcohol is removed through rotary evaporation, water is used for extraction, and finally, the water is removed to obtain 2,2,4,4-tetramethyl-1,3-cyclobutanediol. The method has simple equipment requirement, mild operation condition, low cost and high product purity, and is suitable for industrial production.