Actinide-bearing metal–organic frameworks (MOFs) encompass intriguing structures and properties, but the radioactivity of actinide cripples their applications. Herein, we have constructed a new thorium-based MOF (Th-BDAT) as a bifunctional platform for the adsorption and detection of radioiodine, a more radioactive fission product that can readily spread through the atmosphere in its molecular form or via solution as anionic species. The iodine capture within the framework of Th-BDATfrom both the vapor phase and the cyclohexane solution has been verified, showing that Th-BDATfeatures maximum I2adsorption capacities (Qmax) of 959 and 1046 mg/g, respectively. Notably, the Qmaxof Th-BDATtoward I2from cyclohexane solution ranks among the highest value for Th-MOFs reported to date. Furthermore, incorporating highly extended and π-electron-rich BDAT4–ligands renders Th-BDATas a luminescent chemosensor whose emission can be selectively quenched by iodate with a detection limit of 1.367 μM. Our findings thus foreshadow promising directions that might unlock the full potential of actinide-based MOFs from the point of view of practical application.