The invention discloses a broadband heat-resistant multi-layer film, which belongs to the field of an optical film and is mainly applied in a cover plate of a solar cell. The structure of the film adopts (0.5LH0.5L) 8 (0.44L0.44M0.88H0.44M0.44L) 8 (0.55L0.55M1.1H0.55M0.55L) 7, wherein H represents a highly refractive material with the thickness being one fourth of the designed wavelength, L represents a lowly refractive material with the thickness being one fourth of the designed wavelength, M represents a medium refractive material with the thickness being one fourth of the designed wavelength, the refractive index of the medium refractive material meets the following relation: nM = (nHnL) 1/2, wherein nM represents the refractive index of the medium refractive material, nH represents the refractive index of the highly refractive material, and nL represents the refractive index of the lowly refractive material. The transmission rate of the working band of the cell can be increased toimprove the photoelectric conversion efficiency; the transmission rate of the infrared band can be suppressed to reduce the working temperature of the cell; and the transmission rate of the ultraviolet band can be reduced so as to prolong the service life of the cell.