The invention discloses a bonded silicon PIN radiation response detector based on a tunneling oxide layer and a preparation method thereof. The detector comprises a detection layer silicon wafer and acollection layer silicon wafer bonded together and an ultra-thin silicon dioxide layer located between the two wafers, wherein the front of the detection layer silicon wafer is provided with a P+ region formed by doping, the silicon surface outside the P+ region is covered with a silicon dioxide layer, and the P+ region is covered with a thin metal layer with a field plate structure; the back ofthe collection layer silicon wafer is provided with an N+ region formed by doping completely; the surface of the N+ region is covered with a thick metal layer. The radiation response detector can be used for ultra-fast response measurement in the field of nuclear radiation, and has important applications in the fields of radiation protection and space monitoring.