Preparation device and method for film

The invention discloses a preparation device and a preparation method for a film. The preparation device for a film is used for generation of a film after deposition of gasified powder on a substrate and comprises a gas phase forming unit used for heating powder to form atoms and/or molecular steam, a hot electron generator used for generating hot electrons and enabling the atoms and/or atoms or molecules in the molecular steam output by the gas phase forming unit to carry a weak current through the hot electrons, and an accelerating electrode used for generating an accelerating electric field which accelerates the movement of the atoms or molecules with a weak current and allows the atoms or molecules to be deposited onto the substrate. The invention also discloses the preparation method for the film. The invention has the following advantages: rapid deposition of the film can be realized, high film forming quality is obtained, the film is compact and has strong adhesive power and crystallinity, damage to the substrate and the film is small, convenient control of film forming is achieved.