X-ray detection has been widely used in medical imaging, security inspection, and industrial non-destructive tests. Halide perovskite X-ray detectors have attracted increasing attention due to their high sensitivity and low detection limit, but the notorious ion migration leads to poor operational stability. It is reported that the low dimensional structure can effectively suppress the ion migration of perovskites, thus greatly improving the stability of the detectors. This review introduces the working mechanism, key performance parameters of perovskite X-ray detectors, and summarizes the recent progress of low-dimensional perovskite materials and their application in direct X-ray detectors. The relationship between the structural characteristics of low-dimensional perovskite materials and their X-ray detection performance was systematically analyzed. Low-dimensional perovskite is a promising candidate for the preparation of X-ray detectors with both high sensitivity and stability. Further optimization of detection material and device structure, preparation of large-area pixelated imaging devices, and study of working mechanism in-depth of the detector are expected to promote the practical application of perovskite X-ray detectors.