Metal‐free perovskites are a promising class of materials for X‐ray detection due to their unique structural, optical, and electrical properties. Here, we first delve into the stoichiometry and geometric argument of metal‐free perovskites. Followed, the alternative A/B/X ions and hydrogen‐bonding are clearly introduced to further optimize the materials' stability and properties. Finally, we provide a comprehensive overview of their potential applications for flexible X‐ray images and prospects for metal‐free perovskite development. In conclusion, metal‐free perovskite is a promising material for X‐ray detection. Its stoichiometric and geometric parameters, ion, and hydrogen bond selection, and application prospects are worthy of further study. [ABSTRACT FROM AUTHOR]