The present disclosure provides a method for increasing production of an indigoid compound, including the following steps: (a) subjecting mutation to a wild-type flavin-containing monooxygenase to obtain a mutated flavin-containing monooxygenase; and (b) allowing the mutated flavin-containing monooxygenase to interact with a culture medium containing tryptophan for a predetermined time to convert the tryptophan into the indigoid compound. Compared with the wild-type flavin-containing monooxygenase, the mutated flavin-containing monooxygenase increases production of the indigoid compound. The present disclosure also provides a recombinant polypeptide for increasing production of the indigoid compound. |