A facile modification of a strontium-based MOF using oxalic acid was carried out to prepare MTSr-OX MOF, which was used as a potential substance for eliminating Eu radioisotopes. Various analytical techniques were used to characterize MTSr-OX-MOF. The prepared MOF had a rod-like structure with a BET surface area of 101.55 m g. Batch sorption experiments were used to investigate the sorption performance of MTSr-OX-MOF towards Eu radionuclides where different parameters like pH, contact time, initial Eu concentration, ionic strength, and temperature were scrutinized to determine the optimum conditions for Eu removal. MTSr-OX-MOF showed superior effectiveness in the elimination of Eu with a maximum sorption capacity of 234.72 mg g at pH 3.5. Kinetics fitted with the pseudo-second-order model and the Langmuir model correctly described the sorption mechanism. The thermodynamic variables were carefully examined, demonstrating that the Eu sorption was endothermic as well as spontaneous. The MTSr-OX-MOF has been found to be a significantly more effective sorbent towards Eu than that of many other adsorbents. When applied to real active waste, MTSr-OX-MOF demonstrated excellent removal performance for a wide range of radionuclides. As a result, the MTSr-OX-MOF can be recognized as an attractive solution for the Eu purification from active waste.