A X-ray detector includes: a base substrate; a plurality of detection modules disposed on the base substrate, wherein the detection module includes a thin film transistor disposed on the base substrate, an insulating layer with a via hole disposed on the thin film transistor and a photosensitive structure disposed on the insulating layer, a first electrode of the thin film transistor is electrically connected to the photosensitive structure through the via hole on the insulating layer, and the first electrode is a source or a drain electrode of the thin film transistor; and a scintillation layer disposed on the detection module. In the present disclosure, by disposing the photosensitive structure and the TFT in different layers, the photosensitive area of the photosensitive structure is enlarged, and it will not be affected by the TFT.