The invention discloses a film patterning method and a film patterning device. The film patterning method comprises the following steps: placing a mask above a substrate, wherein the mask has a hollowed portion which is the same as a preset pattern; covering the mask with a film, wherein the film of the hollowed portion of the mask is formed on the substrate, and the remaining region covered with the mask is not covered with the film, thus a patterned film is formed on the substrate. By adopting the film patterning method, the pattern on the mask can be directly transferred onto the substrate by means of one-step deposition, the process steps of photoetching an etching are eliminated, the process flow is simplified greatly, and the cost of film patterning is saved.