A metal atomic layer deposition solar energy high-selective endothermic heating film and a preparation method are disclosed. The raw material is composed of nano metal powder and ethanol, the mass ratio of nano metal powder to ethanol is 1:8-10, and the nano metal powder is made of metal chromium powder, metal manganese powder and metal copper powder. The mass ratio of each component in the nano metal powder is: metal chromium powder: metal manganese powder: metal copper powder is 6-8:1 to 3:1, and direct oxidation and sintering of nano metal and a single atomic layer deposition method are adopted. The endothermic film layer produced by the process of the invention is tested by the National Solar Water Heater Quality Inspection Supervision Center: the absorption rate reaches 96%, the emissivity is 9%, and the optical performance index is very excellent. The process can realize the batching production of the aluminum coil to the aluminum coil, further reduces production cost and expandproduction capacity, and has a good market prospect and social effects.