Copper-based metal halides are a group of potential scintillation materials with non-toxic and environmentally friendly properties. However, the slow growth rate of their crystals hinders their applications. In this paper, an organic [N(C2H5)4]2Cu2Br4 crystal was proposed for X-ray scintillation imaging. It was successfully synthesized using a fast solution-phased approach with a production rate of 100 mg/min. The photoluminescence quantum yield of the [N(C2H5)4]2Cu2Br4 crystal is 55% with good stability. More importantly, it has a bright blue emission with a large Stokes shift originating from self-trapped excitons, which contribute to the reabsorption-free characteristic. Its scintillation properties, with a light yield of 7623 photons MeV−1 and remarkable X-ray imaging performance, provide important guidance for the further study of X-ray scintillation crystals.