Provided is a method for recycling energy in process of butadiene preparation, which includes, in the process of preparing butadiene using oxidative dehydrogenation reaction, steps of: a) supplying part or all of a light gas discharged from a solvent absorption tower to a turbine to produce electricity; b) passing the light gas passed through the turbine through one or more device units provided with a heat exchanger; and c) feeding the light gas passed through the device units provided with the heat exchanger into a reactor, according to which more economical butadiene preparation process is provided, by reducing net energy value required in process of butadiene preparation using oxidative dehydrogenation reaction.