The present invention provides an optical film assembly mounting structure, which includes: a first mold frame (6), a second mold frame (8) arranged on the first mold frame (6), and an optical film assembly (9) arranged between the first and second mold frame (6, 8). The first mold frame (6) carries the optical film assembly (9) thereon and the second mold frame (8) is positioned on and presses down the optical film assembly (9) so as to achieve secure mounting of the optical film assembly (9). The first mold frame (6) includes an inclined first upper surface (61). The second mold frame (8) includes a first bottom surface (81) and a second bottom surface (83) connected to the first bottom surface and having an inclination angle identical to that of the first upper surface (61). The optical film assembly (9) is positioned on the first upper surface (61) and the first and second bottom surfaces (81, 83) are positioned on and press down the optical film assembly (9).