NOVELTY - Solar energy selective absorption film system comprises aluminum foil as a substrate, and the absorption film system sequentially comprises a double layer aluminum nitride film as an antireflection layer, a single layer titanium oxynitride (I) film adopted as an absorption layer, a single layer aluminum film adopted as an infrared reflection layer and a substrate aluminum foil from the top layer to the bottom layer, where rose petal-shaped structures are uniformly distributed on the substrate aluminum foil, and a distance h between petal centers is 300-2100 nm.    USE - Used as a solar energy selective absorption film system.    ADVANTAGE - The rose petal-shaped structures are uniformly distributed on the aluminum substrate foil, and a distance h between petal centers is more than 300-2100 nm so as to achieve absorption of visible light and near-infrared light and a reflection effect on infrared light.    DETAILED DESCRIPTION - Solar energy selective absorption film system comprises aluminum foil as a substrate, and the absorption film system sequentially comprises a double layer aluminum nitride film as an antireflection layer, a single layer titanium oxynitride of formula (TiNxOy) (I) film adopted as an absorption layer, a single layer aluminum film adopted as an infrared reflection layer and a substrate aluminum foil from the top layer to the bottom layer, where rose petal-shaped structures are uniformly distributed on the substrate aluminum foil, and a distance h between petal centers is 300-2100 nm.    x, y = 7:1    An INDEPENDENT CLAIM is also included for preparing the solar energy selective absorption film system, comprising: cleaning aluminum substrate and preparing into microstructure, carrying out single-step preparation of aluminum substrate microstructure into single layer aluminum film, preparing single layer titanium oxynitride film and double layer aluminum nitride film as an antireflection layer, where the step of cleaning aluminum substrate and preparing into microstructure comprises: preparing silicone solution and pouring on a clean flat rose petals, placing into the oven without air bubbles, set the oven temperature as 60 degrees C, removing after 10 hours, and isolating polydimethylsiloxane (PDMS) template with rose petal anti-structure, cleaning the aluminum foil, placing into etching machine, using pre-designed mask pattern and etching the substrate surface into microstructure, where the etching time is 5 minutes, and the etching process is carried out using nitrogen as protective gas, with flow rate of 20 standard cubic centimeters per minute (sccm), and petal center distance of 300 nm.