A medical image-based radiation shielding device and method thereof, which may form a targeted and highly accurate radiation shielding according to individual differences in patients, such as tumor location and size, thereby reduce or avoid radiation from a irradiation apparatus to normal tissues of patients. The shielding device includes a medical image scanning means for scanning an irradiated site of an irradiated subject and outputting medical image voxel data, a data processing and three-dimensional modeling means for establishing a three-dimensional phantom tissue model according to the medical image voxel data and establishing a three-dimensional shield model according to the three-dimensional phantom tissue model； a shield located between the irradiation apparatus and the irradiated site, wherein the shield is formed by printing the three-dimensional shield model data input to a 3D printer.
