X-ray flat panel detector and preparation method thereof as well as white insulation material

The invention discloses an X-ray flat panel detector and a preparation method thereof as well as a white insulation material. The X-ray flat panel detector comprises a film transistor base plate, an insulation layer, a pixel electrode, a photodiode, an electrode and an X-ray transfer layer, wherein the insulation layer is arranged on the film transistor base plate and has a reflection effect, and is provided with a contact whole exposing a source electrode of the film transistor base plate; the pixel electrode is arranged on the insulation layer, and is conducted with the source electrode of the film transistor base plate via the contact hole; the photodiode covers the pixel electrode; the electrode is arranged on the photodiode; the X-ray transfer layer is arranged on the electrode. The X-ray flat panel detector has high quantum detection efficiency and sensitivity.