A backlight module is disclosed. The backlight module comprises a first optical film, a second optical film, a backplate frame, and an optical film supporting device adapted to splice and support the first optical film and the second optical film. The optical film supporting device comprises a body, a splicing portion and a fixing portion. The splicing portion is adapted to splice and support the first optical film and the second optical film, and the fixing portion is fixed to the backplate frame. A liquid crystal display (LCD) device comprising the backlight module described above is also disclosed. By providing an optical film supporting device in the backlight module of the present invention, two or more optical films can be spliced by the optical film supporting device to satisfy the demands for a large-sized optical film. This solution is practical, reliable and low in the cost.