X-ray　detectors　based　on　scintillators　are　widely　used　in　the　fields　of　medical　imaging,　high-energy　physics,　geological　exploration,　and　industrial　detection.　The　development　of　scintillation　materials　with　different　characteristics　has　become　the　focus　of　considerable　research　interest.　Herein,　we　report　a　facile　hydrothermal　synthesis　of　Gd-　and　Eu-codoped　LiLuF4　microcrystals　(MCs),　which　exhibit　strong　luminescence　of　Eu3+　ion　characteristic　emission,　characterized　by　distinct　red　fluorescence　emission.　The　research　shows　that　Gd3+　co-doping　effectively　improved　the　sensitivity　and　light　yield　of　LiLuF4:Eu　MCs　by　regulating　the　proportion　of　co-doping　ions.　In　addition,　the　detection　limit　is　140.72　nGy　s−1　for　LiLuF4:Eu,Gd　MCs,　approximately　39　times　lower　than　the　dose　requirement　of　medical　diagnosis.　Based　on　LiLuF4:Eu,Gd　MCs　with　the　superior　scintillation　properties,　a　MC-composited　film　with　250　μm　thickness　was　prepared　by　a　direct　coating　method.　The　uniform　and　high-loading　scintillation　film　exhibits　outstanding　imaging　performance　with　a　high　spatial　resolution　of　14.8　LP　mm−1,　which　confirms　the　application　potential　of　X-ray　imaging.　©　2024　The　Royal　Society　of　Chemistry.