LAUSR

High‐energy radiation is widely used in medicine, industry, and scientific research. Meanwhile, the detection of environmental ionizing radiation is essential to ensure the safe use of high‐energy radiation. Among radiation detectors, scintillator detectors offer multiple advantages, including simple structure, high sensitivity, excellent environmental adaptability, and a favorable performance‐to‐price ratio. However, the development of high‐performance scintillators that can provide highly sensitive responses to environmental radiation, especially α/β particles, remains a challenge. In this work, a copper cluster (Cu4I4(DPPPy)2) with excellent water‐oxygen stability is prepared using a simple one‐pot method at room temperature. Cu4I4(DPPPy)2 not only exhibits excellent X‐ray excited luminescence (XEL) under X‐ray irradiation but also demonstrates a highly sensitive scintillation response to α/β particles. By integrating Cu4I4(DPPPy)2 with a photomultiplier tube (PMT) and nuclear electronics, an α/β surface contamination monitor is successfully developed. This monitor enables the sensitive detection of excessive α/β particles in real‐world environments. The detection frequency and signal intensity of Cu4I4(DPPPy)2 significantly surpass those of commercial scintillator of YAP:Ce, BGO, PbWO4, and anthracene under identical conditions, highlighting the promising application of metal clusters in low‐dose environmental radiation detection.