NOVELTY - A laser direct writing film comprises a first medium layer, a metal oxide layer, a second medium layer, and a glass substrate; where it is formed by using the magnetic control sputtering instrument to sequentially sputter the first medium layer, the metal oxide layer, and the second medium layer on the glass substrate; where the metal oxide of the metal oxide layer is silver oxides, platinum oxides, or palladium oxides; and the first medium layer and the second medium layer are made of zinc sulfide-silicon dioxide, silicon nitride, or silicon dioxide.    USE - The laser direct writing film is useful in fields comprising solar cell and liquid crystal display.    ADVANTAGE - The laser direct writing film has strong adhesive attraction between the film and the substrate, fine parameter controllability, and high film density.    DETAILED DESCRIPTION - A laser direct writing film comprises a first medium layer, a metal oxide layer, a second medium layer, and a glass substrate; where it is formed by using the magnetic control sputtering instrument to sequentially sputter the first medium layer, the metal oxide layer, and the second medium layer on the glass substrate; where the metal oxide of the metal oxide layer is silver oxides (AgOx), platinum oxides (PtOx), or palladium oxides (PdOx); the film is 100-300 nm or 8-12 nm thick; and the first medium layer and the second medium layer are made of zinc sulfide-silicon dioxide (ZnS-SiO2), silicon nitride (SiN), or silicon dioxide (SiO2). An INDEPENDENT CLAIM is a preparation method of the laser direct writing film comprising: (a) washing the glass substrate; where the surface roughness of the glass substrate is less than 10 nm; and the glass substrate is taken out and dried by pure high pressure nitrogen after being soaked by pure water, washed by pure water ultrasonically, and washed by absolute ethyl alcohol ultrasonically; (b) mounting the glass substrate and sputtering target: fixing the glass substrate on the glass substrate tray of the magnetic control sputtering instrument, clamping the glass substrate tray on the substrate base in the magnetic control sputtering vacuum cavity, placing selected sputtering medium target and metal target on corresponding target bases, fixing, adjusting the distance between the target and the glass substrate, closing the vacuum cavity cover, vacuumizing until the vacuum pressure is4x 10-4 Pa; (c) sputtering the first medium film layer, using argon (Ar) as base gas, using the computer to control the glass substrate to transfer to the upper side of the medium target, opening the Ar gas valve, charging Ar to the magnetic control sputtering vacuum cavity, controlling the connecting quantity of the Ar gas as 80 standard cubic centimeter (sccm), simultaneously adjusting the working air pressure of the gate valve of the magnetic control sputtering instrument to 0.8 Pa, opening the radio frequency power supply of the magnetic control sputtering instrument, adjusting the power of the target for sputtering, using the computer program to control the sputtering time, sputtering the first medium layer, after sputtering, closing the radio frequency power supply, closing Ar gas valve, opening the gate valve, pumping, removing the impurities in the magnetic control sputtering vacuum cavity; (d) sputtering the metal oxide film layer, using the computer to control the glass substrate to transfer to the upper side of the metal target to be sputtered, simultaneously opening the oxygen (O2) gas valve and Ar gas valve, charging gas to the magnetic control sputtering vacuum cavity, controlling the connecting quantity of the 02 gas as 90 sccm, connecting quantity of the Ar as 10 sccm, simultaneously adjusting the working air pressure of the gate valve of the magnetic control sputtering instrument to 0.8 Pa, opening the radio frequency power supply of the magnetic control sputtering instrument, adjusting the power of the target for sputtering to 100 W, using the computer program to control the sputtering time, sputtering the metal oxide layer, after sputtering, closing the radio frequency power supply, closing O2 and Ar gas valves, opening the gate valve, pumping, removing the residual gas and impurities in the magnetic control sputtering vacuum cavity; (e) sputtering the second medium film layer, using Ar as base gas, using the computer to control the glass substrate to transfer to the upper side of the medium target, opening the Ar gas valve, charging Ar to the magnetic control sputtering vacuum cavity, controlling the connecting quantity of the Ar gas as 80 sccm, simultaneously adjusting the working air pressure of the gate valve of the magnetic control sputtering instrument to 0.8 Pa, opening the radio frequency power supply of the magnetic control sputtering instrument, adjusting the power of the target for sputtering to 100 W, using the computer program to control the sputtering time, sputtering the lower medium layer, after sputtering, closing the radio frequency power supply, closing Ar gas valve, opening the gate valve, pumping, removing the impurities in the magnetic control sputtering vacuum cavity; and (f) using the computer program to cause the glass substrate to recover to the initial position, closing the magnetic control sputtering instrument, discharging, opening the magnetic control sputtering vacuum cavity, and taking out the laser direct writing film.