The invention provides a butanone preparation and refining method. The method includes: (A), subjecting sec-butyl acetate and hydrogen to hydrogenation reaction in a fixed-bed reactor filled with hydrogenation catalyst; (B), feeding a hydrogenation product obtained in the step (A) into a crude alcohol separating tower for separation so as to obtain crude ethanol at the tower top, and feeding tower bottom components into a sec-butyl alcohol refining tower for refining; (C), preheating high-purity sec-butyl alcohol obtained at the tower top of the sec-butyl alcohol refining tower prior to feeding the preheated high-purity sec-butyl alcohol into a dehydrogenation reactor filled with dehydrogenation catalyst for dehydrogenation reaction; (D), feeding a dehydrogenation product obtained in the step (C) into a butanone drying tower via a buffer tank, supplementing entrainer from the top of a return tank, and removing water in crude butanone by means of azeotropic distillation; (E), feeding the dewatered crude butanone in the step (D) into a butanone refining tower for distillation so as to obtain butanone with the mass fraction above 99% from the top of the butanone refining tower.