Precise　monitoring　of　biomolecular　radiation　damage　is　crucial　for　understanding　X-ray-induced　cell　injury　and　improving　the　accuracy　of　clinical　radiotherapy.　We　present　the　design　and　performance　of　lanthanide-DNA-origami　nanodosimeters　for　directly　visualizing　radiation　damage　at　the　single-particle　level.　Lanthanide　ions　(Tb3+　or　Eu3+)　coordinated　with　DNA　origami　nanosensors　enhance　the　sensitivity　of　X-ray　irradiation.　Atomic　force　microscopy　(AFM)　revealed　morphological　changes　in　Eu3+-sensitized　DNA　origami　upon　X-ray　irradiation,　indicating　damage　caused　by　ionization-generated　electrons　and　free　radicals.　We　further　demonstrated　the　practical　applicability　of　Eu3+-DNA-origami　integrated　chips　in　precisely　monitoring　radiation-mediated　cancer　radiotherapy.　Quantitative　results　showed　consistent　trends　with　flow　cytometry　and　histological　examination　under　comparable　X-ray　irradiation　doses,　providing　an　affordable　and　user-friendly　visualization　tool　for　preclinical　applications.　These　findings　provide　new　insights　into　the　impact　of　heavy　metals　on　radiation-induced　biomolecular　damage　and　pave　the　way　for　future　research　in　developing　nanoscale　radiation　sensors　for　precise　clinical　radiography.