The present disclosure discloses a backlight module and the manufacturing method thereof. The backlight module comprises a substrate, a plastic frame, a light guide plate, and a film set. The plastic frame is formed on the substrate through printing, which forms a housing space together with the substrate. The light guide plate and the film set are sequentially stacked in the housing space. The backlight module according to the present disclosure will not affect the display of the liquid crystal display panel during thermal expansion.