[en] A self-supported PC membrane was prepared through chemical vapor deposition process, and CsI was evaporated onto PC surface. Then a large-area self-supported CsI/PC membrane was prepared. The thickness of PC membrane was 300 nm, and that of CsI membrane was controlled between 100 nm to 1 μm. The effects of deposition speed and deliquescence on morphology and structure were analyzed by SEM and XRD. The photoelectric conversion property was analyzed by Manson X-ray source. The energy spectral response peak value of CsI/PC membrane was above 3000 μA/W which was calibrated at Beijing synchrotron radiation facility. The membrane was applied to X-ray streak camera on SG Ⅲ facility and distinct X-ray images were captured. (authors)