The invention discloses a bifunctional light conversion thin film, which is characterized by comprising a thin film substrate, a bifunctional light conversion agent and a first additive, wherein the weight of the bifunctional light conversion agent accounts for 0.1-10% of the weight of the thin film; the weight of the first additive accounts for 0.1-10% of the weight of the thin film; the rest of the thin film is the thin film substrate; the general formula of the bifunctional light conversion agent is Ca(1-x)NxF2: Eu, TM, wherein x is greater than or equal to 0 and less than or equal to 1, N refers to one or more of Ba, Zn, Sr, Mg, Hg and Fe, and TM is selected from one or more of Sm, Cu, Pr, Dy, Tb, Ce, La, Mn and Ag. The bifunctional light conversion thin film disclosed by the invention is good in stability, high in luminous intensity, adjustable in blue / red orange light intensity, and long in service life. The bifunctional light conversion thin film disclosed by the invention can convert ultraviolet light (300-380 nm) and green light (520-560 nm) in sun light into strong blue light (400-500 nm) and red orange light (575-630 nm) capable of promoting the growth of crops.