An exemplary backlight module (100) includes a housing (10), a reflective sheet (30), a number of point light sources (20). The housing includes a bottom plate (12) and at least one platform support (14) extending out from the bottom plate towards an interior of the housing. The reflective sheet is supported by the platform support, and defines a number of through holes (301). The point light sources are arranged in the housing corresponding to the through holes of the reflective sheet. Each point light source includes a base portion (22) and a light emitting portion (24). The base portion is secured at the bottom plate of the housing, and the light emitting portion protrudes through a corresponding one of the through holes.