Production method of biobutanol using wastewater obtained from biobutanol separation process

Provided is a production method of biobutanol, which includes the steps of: producing biobutanol by fermenting biomass using a first microorganism having an ability of producing butanol; separating and refining the butanol from the fermented product with 60% or more of butanol selectivity; collecting wastewater produced in the previous step of separating and refining; preparing a culture medium including the wastewater; and culturing a second microorganism in the culture medium.