The present invention relates to an X-ray line array detector in which a bundle of light-guide fibers is provided between an emergent surface of a scintillator and an incident surface of an array of photosensors, and the bundle of light-guide fibers has at least one bend, or an incident direction and an emergent direction are not in a same line, so that X-rays transmitting through the scintillator can not irradiate photosensors and integrated circuits behind them, and that damage resulting from long-term use or a large dose of X-ray radiation can be avoided, thereby prolonging lifetime of the line array detector. Further, a shielding body provided between the emergent surface of the scintillator and the incident surface of the array of photosensors can further shield the photosensors and their integrated circuits from interference of X-rays, so that good protection of the photosensors and their integrated circuits is achieved, thereby enhancing greatly anti-radiation performance of the detector and doubling the lifetime.