The invention discloses a quantum well infrared detector of multiple light scattering coupling. The detector comprises a substrate layer, a lower electrode layer which grows successively layer by layer, a multiple quantum well layer with 50 periods and an upper electrode layer. An array layer made of metallic balls which are immersed in organic adhesive or balls which are coated with metal is provided on the upper electrode layer. The array layer is provided with a metal contacting layer, and the metal contacting layer is provided with a readout circuit by means of flip-chip bonding interconnection to realize the readout detection signals. The invention has the advantages that: firstly, the metal ball array replaces the traditional grating. The electric rector which can be absorbed with transition by a quantum well belt is produced by multiple light coupling among the metallic balls. The electric rector parallels to the component of the quantum well layer, so the coupling between the normal incidence lights and the quantum well is realized. Secondly, the metallic ball array replaces the traditional indium column of flip-chip bonding interconnection to form an anisotropic conducting layer, so the conductive function is realized. Because of the advantages, on one hand, the coupling efficiency of normal incidence lights is improved; on the other hand, the deposition of indium bump is saved, and the flip-chip bonding process is simplified.