This study presents a high-performance dynamic direct-conversion CMOS X-ray detector fabricated using screen-printed CsPbBr3 perovskite material. The detector offers ultra-high spatial and temporal resolution, with a mobility-lifetime product of 5.2 × 10^-4 cm^2 V^-1 and an X-ray sensitivity of 1.6 × 10^4 μGyair^-1 cm^-2. The detector can achieve rapid imaging at a speed of 300 frames per second and provides high spatial resolution (5.0 lp mm^-1) at low radiation doses (260 nGy). It successfully reconstructs 3D tomographic images of biological specimens, demonstrating its potential in high-resolution, large-area, low-dose dynamic biomedical X-ray and CT imaging, as well as in non-destructive X-ray testing and security scanning. The use of lead halide perovskites offers a promising approach for developing next-generation X-ray detectors with enhanced performance, making conventional medical X-ray imaging more gentle and safe.This study presents a high-performance dynamic direct-conversion CMOS X-ray detector fabricated using screen-printed CsPbBr3 perovskite material. The detector offers ultra-high spatial and temporal resolution, with a mobility-lifetime product of 5.2 × 10^-4 cm^2 V^-1 and an X-ray sensitivity of 1.6 × 10^4 μGyair^-1 cm^-2. The detector can achieve rapid imaging at a speed of 300 frames per second and provides high spatial resolution (5.0 lp mm^-1) at low radiation doses (260 nGy). It successfully reconstructs 3D tomographic images of biological specimens, demonstrating its potential in high-resolution, large-area, low-dose dynamic biomedical X-ray and CT imaging, as well as in non-destructive X-ray testing and security scanning. The use of lead halide perovskites offers a promising approach for developing next-generation X-ray detectors with enhanced performance, making conventional medical X-ray imaging more gentle and safe.