Abstract: A short-wave infrared detector unit device and a preparation method therefor are provided, which belongs to the technical field of infrared detectors. A photonic crystal structure layer with multi-coupled topological defects is arranged on a surface of an absorption layer. The photonic crystal structure layer with multi-coupled topological defects is a third dielectric material layer with a through-hole structure. The third dielectric material layer is provided with first through holes in periodic arrangement and second through holes in periodic arrangement. The first through holes are filled with a first dielectric material, and the second through holes are filled with a second dielectric material.