The low heat dissipation efficiency will cause damage to the electronic devices. Here, we proposed a radiative cooling foil with simple double-layer structure composed of a transparent fluorinated polyimide embedding SiO2 microspheres and a silver layer(FPI@SiO2/Ag). The foil was prepared by a simple in-situ polymerization, and the thermal analysis shows that the foil has an outstanding thermal stability with the glass transition temperature of 194∘C. We experimentally and theoretically performed the investigation of spectra, thermal radiative property, and cooling performance at different condition. We demonstrated that the 3 wt% FPI@SiO2/Ag foil can achieve radiative cooling to 4.6 ± 0.2∘C under direct sunlight. The foil shows a strong broadband thermal radiation with emissivity approaching 0.94 ± 0.03 at 8–13 μm wavelengths and 0.92 ± 0.03 at 2.5–25 μm wavelengths, yet ultralow solar absorptivity with 0.07 ± 0.02. The radiative cooling foil that can withstand high temperature is very attractive to apply regardless of the terrestrial structure and the space lander.