A ray detector and a ray detection panel. The ray detector includes a base substrate, a thin film transistor, a scintillator, and a photodetector; the scintillator is located on aside of the photodetector that is away from the base substrate; the photodetector includes: a first conductive structure; a semiconductor layer; a second conductive structure; a first dielectric layer; and a second dielectric layer, the second conductive structure is electrically connected with source electrode; the thin film transistor is located between the base substrate and the photodetector; and an orthographic projection of the thin film transistor on the base substrate at least partially falls into an orthographic projection of the photodetector on the base substrate.