The　architectural　design　and　fabrication　of　low-cost,　high-performance　organic　scintillators　are　critical　for　medical　imaging　and　material/device　analysis.　However,　achieving　large-area　and　high-transparency　organic　scintillators　in　a　low-cost　and　easy-to-implement　method　remains　a　challenge.　Herein,　a　new　design　strategy　for　regulating　the　side　chain　length　of　maleimide　derivatives　is　demonstrated　to　develop　organic　scintillators　for　achieving　low-cost,　large-area,　and　high　spatial　resolution　in　X-ray　imaging.　The　effective　intermolecular　interactions　and　relatively　twisted　molecular　structure　endow　PAM-M4　molecule　with　outstanding　scintillator　properties.　More　importantly,　as　demonstrated　for　the　first　time,　pure　organic　glassy　films　with　a　diameter　over　10 cm　and　high　optical　transparency　can　be　prepared　by　the　developed　melt-quenched　method　using　PAM-M4　crystal　powder　as　a　raw　material.　This　glassy　film　exhibits　excellent　X-ray　imaging　ability　with　a　spatial　resolution　as　high　as　27.0 lp mm−1　at　MTF = 0.20,　which　is　one　of　the　best　results　among　reported　organic　scintillators.　The　results　of　this　work　not　only　develop　a　new　design　strategy　for　high-performance　organic　scintillators　but　also　demonstrate　a　reliable　approach　to　fabricating　large　area　screens　with　superior　spatial　resolution　for　medical　or　industrial　X-ray　imaging　applications.　©　2024　Wiley-VCH　GmbH.