Solution-processed　scintillators　hold　great　promise　in　fabrication　of　low-cost　X-ray　detectors.　However,　state　of　the　art　of　these　scintillators　is　still　challenging　in　their　environmental　toxicity　and　instability.　In　this　study,　we　develop　a　class　of　tetradecagonal　CuI　microcrystals　as　highly　stable,　eco-friendly,　and　low-cost　scintillators　that　exhibit　intense　radioluminescence　under　X-ray　irradiation.　The　red　broadband　emission　is　attributed　to　the　recombination　of　self-trapped　excitons　in　CuI　microcrystals.　We　demonstrate　the　incorporation　of　such　CuI　microscintillator　into　a　flexible　polymer　to　fabricate　an　X-ray　detector　for　high-resolution　imaging　with　a　spatial　resolution　up　to　20　line　pairs　per　millimeter　(lp　mm(-1)),　which　enables　sharp　image　effects　by　attaching　the　flexible　imaging　detectors　onto　curved　object　surfaces.