Herein, a novel p-n type BiOBr/Znx@SnO2-n photocatalyst was designed by using BiOBr coupling with large specific surface area Zn doped SnO2 through a facile in situ approach. The composite possesses proper redox potential as well as high efficiency interfacial charge transfer capability. Coupling BiOBr with Zn doped SnO2 is proved efficiency to form a facile bandgap regulation mechanism and could adjust the absorption capacity of visible light, thus enhances the photocatalytic performance effectively. The photocatalyst exhibits high efficiency in photo-reforming of fructose to lactic acid under alkaline conditions, achieving a maximum yield of 79.6% and still achieving a lactic acid yield of 70.7% even after five cycles of recycling. Possible pathways of the lactic acid production were proposed based on the generation of active oxidative radicals and the products detected during the reaction. Therefore, this work provides an effective approach for biomass conversion through rational photocatalyst design.