With the growing demand for X-ray imaging, especially for three-dimensional objects with curved surfaces, a large-area flexible X-ray imaging membrane based on scintillating materials becomes the focus of vigorous investigation. Among the developed scintillators, metal-organic frameworks (MOFs) featuring tunable photophysical properties and marked luminescence stability hold great promise for serving as ideal X-ray scintillators. Here, we report a flexible composite scintillating membrane with superior imaging performance. The membrane is achieved by embedding an aggregation-induced emission (AIE) luminogen (AIEgen, H4ETTC)-functionalized MOF scintillator (Y-PCN-94) into a polymer matrix (PDMS). Notably, Y-PCN-94 exhibits a strong AIE effect under both ultraviolet (UV) light and X-ray irradiation, which is also the first time that the AIE effect was observed in the MOF system under an ionizing radiation field. This also gives the material promising radioluminescence properties, such as a low X-ray detection limit (1.6 μGy s-1) and high imaging resolution (>14.3 lp mm-1), which can be mainly attributed to the combination of the AIE effect and strong X-ray stopping power. This work demonstrates that incorporating AIEgens into MOFs or other frameworks can offer an alternative approach for producing high-performance X-ray scintillators.