The invention provides a backlight module. The backlight module comprises a back plate, a reflection sheet, a light guide plate, an optical film, a light source, an optical processing assembly and an optical filter assembly, wherein the reflection sheet is arranged on an inner bottom surface of the back plate; the light guide plate is arranged on the reflection sheet; the optical film is arranged on the light guide plate; the light source is arranged on an inner side surface of the back plate; the optical processing assembly is arranged between the light source and a lateral in-light surface of the light guide plate; and the optical processing assembly comprises: an optical filter assembly which is used for filtering light with pre-set wavelength in light generated by the light source and is used for providing filtered light to the lateral in-light surface of the light guide plate. The backlight module provided by the invention can enable the light emitted from the backlight module to have a relatively high color gamut.