A light guide plate and a method of manufacturing the same, and a backlight module, are disclosed. The light guide plate comprises: a transparent substrate having a light emergence face, a bottom face opposite to the light emergence face, and a plurality of side faces connecting and perpendicular to the light emergence face and the bottom face; and a scattering layer and a first reflective film layer, wherein the scattering layer is formed on the light emergence face of the transparent substrate and the first reflective film layer is formed on the bottom face of the transparent substrate, or the scattering layer is formed on the bottom face of the transparent substrate and the first reflective film layer is formed on the scattering layer.