A backscatter detection module includes: a plate-like light-transmitting carrier, two layers of scintillators and a light sensor. The light-transmitting carrier is made of a material that allows fluorescence photons to pass through, and has two light-transmitting planes opposite to each other and at least one light emergent end surface; the light emergent end surface is located between the two light-transmitting planes; the two layers of scintillators are respectively fixedly attached to the two light-transmitting planes; the light sensor is coupled to the light emergent end surface.