A flat panel detector is provided, which includes a substrate and a plurality of photodiodes on the substrate. The flat panel detector further includes a first transparent conductive layer disposed on a side of the photodiodes away from the substrate. An orthographic projection of the first transparent conductive layer on the substrate at least partially overlaps the orthographic projection of each photodiode of the plurality of photodiodes on the substrate. The flat panel detector can mitigate or reduce the influence of external static electricity and improve the working stability.