The invention provides a backlight module. The backlight module comprises a frame, lighting units and light mixing plates, wherein the lighting units are configured on the inner surface of the frame, and the light mixing plates are arranged above the lighting units; a plurality of penetrating parts are distributed on the lighting mixing plates, provided with through holes with different pore diameters, arranged for energy density of light emitted by the lighting units and distributed on the lighting mixing plate, and used for providing lower light permeability for areas with higher light energy density as well as providing higher light permeability for areas with lower light energy density so as to realize the purpose of uniform light mixing.