Total reflection lens group diaphragm and backlight module

The invention provides a total-reflection lens group diaphragm and a backlight module. The backlight module comprises a light-emitting plate, the total-reflection lens group diaphragm and a light equalizing diaphragm which are sequentially arranged in the light propagation direction. The total-reflection lens group diaphragm comprises a sheet layer area and a plurality of total-reflection lens monomers; the light-emitting surface of the lamellar region is a plane; the total-reflection lens units are arranged on the side face, opposite to the light-emitting face, of the lamella area, a groove is formed in the middle of the end of each total-reflection lens unit, each groove is provided with an opening and a groove bottom curved face facing the opening, each total-reflection lens unit is provided with a surrounding curved face, and the surrounding curved faces are connected with the end face of the end and the side face of the lamella area. According to the backlight module, only two optical elements including