The invention provides a mixed refrigerant and a refrigerating device with the same. The mixed refrigerant comprises trifluoroiodomethane, propylene and a third component, and the third component is selected from 2,3,3,3-tetrafluoropropene and/or trans-1,3,3,3-tetrafluoropropene. The mixed refrigerant comprises multiple refrigerants, and by exerting the synergistic effect of the refrigerants, themixed refrigerant has a low GWP value (lower than 100) and a high volumetric refrigerating capacity and volumetric heating capacity; the trifluoroiodomethane has excellent flame retardancy, thus, theaddition of the trifluoroiodomethane can weaken the flammability of the refrigerants, and then the safety of the mixed refrigerant is improved. Thus, by adopting the mixed refrigerant for refrigeration, the refrigerating and heating effects of the mixed refrigerant can be improved, the problems that an existing R134a refrigerant has a low low-temperature heating capacity and a high GWP value are solved, and substances harmful to the environment will not be generated in the refrigerating process.