Provided is a method of manufacturing a module structure for photomicro-reactors. The method of manufacturing a module structure for photomicro-reactors according to an aspect of the present invention, which is a method of manufacturing the module structure for photomicro-reactors inside which a reactant and a photocatalyst flow and photochemically react, includes mixing a polymer and a photoinitiator to prepare a photocurable resin, exposing one region of a surface of the photocurable resin to ultraviolet light to form a unit layer having a predetermined thickness, placing the photocurable resin on an upper side of the unit layer, and forming and stacking a plurality of the unit layers by repeatedly performing the forming of the unit layer and the placing of the photocurable resin to form the module structure.