X-ray　imaging　is　a　low-cost,　powerful　technology　that　has　been　extensively　used　in　medical　diagnosis　and　industrial　nondestructive　inspection.　The　ability　of　X-rays　to　penetrate　through　the　body　presents　great　advances　for　noninvasive　imaging　of　its　internal　structure.　In　particular,　the　technological　importance　of　X-ray　imaging　has　led　to　the　rapid　development　of　highperformance　X-ray　detectors　and　the　associated　imaging　applications.　Here,　we　present　an　overview　of　the　recent　development　of　X-ray　imaging-related　technologies　since　the　discovery　of　X-rays　in　the　1890s　and　discuss　the　fundamental　mechanism　of　diverse　X-ray　imaging　instruments,　as　well　as　their　advantages　and　disadvantages　on　X-ray　imaging　performance.　We　also　highlight　various　applications　of　advanced　X-ray　imaging　in　a　diversity　of　fields.　We　further　discuss　future　research　directions　and　challenges　in　developing　advanced　next-generation　materials　that　are　crucial　to　the　fabrication　of　flexible,　low-dose,　highresolution　X-ray　imaging　detectors.　©　2021　Xiangyu　Ou　et　al.