We reported a stretchable and flexible radiation-shielding film based on room-temperature liquid metal. Conceptual experiments showed that the liquid metal based printing technology can achieve an ultrathin flexible radiation-shielding film with a thickness of 0.3 mm. Moreover, the yield strength and ultimate strength of the liquid metal film appear much better than those of a conventional lead-particle-containing radiation-shielding material. In order to evaluate the radiation-shielding performance of the liquid metal material, X-ray radiation experiments to compare the liquid metal film and conventional lead-particle-based shielding material under different stretching conditions were performed. The results indicate that the liquid metal shielding film could achieve a certain radiation-shielding performance. Furthermore, because of the screen-printing properties of liquid metal, a low-cost X-ray mask method using a liquid metal selective radiation-shielding film was also studied, which could serve as a highly efficient and practical method for the medical X-ray shielding applications or semiconductor lithography industry.