The invention discloses a method for culturing a biofilm by sectional flow of nano material mixed liquid in a microchannel. The inner wall of the microchannel is modified by a silane reagent; after the modification is completed, a pre-cultured recombinant strain is introduced into a pipeline by a micro-flow pump through the microchannel; after the strain is implanted and fixed in the pipeline, a culture solution containing a nano material is introduced; single-phase flow culture is adopted; and then sterilized air is injected by a T-shaped joint connected with a second micro-flow pump, and a segmented flow of an air/nano material mixed culture solution is adopted to culture a strain in a microchannel reactor so as to prepare a biofilm growing stably. The method is novel in design, simple and convenient to operate and mild in condition, solves the technical problems of difficult field planting of recombinant Escherichia coli in the microchannel reactor and uncontrollable biofilm growth,realizes controllable preparation of the biofilm in the microchannel, and obviously improves the permeability of the biofilm.