Membrane material positioning structure, backlight module and display device

The utility model provides a membrane material positioning structure which comprises a back plate, a protruding structure protruding from the side wall of the back plate to the center of the back plate in the X-axis direction is arranged on the side wall of the back plate, and a groove structure matched with the protruding structure is arranged at the corresponding position of a membrane material. The groove structure is recessed from the edge of the membrane material to the center of the membrane material in the X-axis direction. According to the membrane material positioning structure, positioning of the membrane material in the horizontal direction and the vertical direction is achieved only through the two step type convex lugs of the membrane material, assembling is convenient, production line loss is reduced, batch production is facilitated, forming of a groove in the back plate is avoided, black adhesive tape does not need to be used for membrane material positioning, the production cost is reduced, and the production efficiency is improved. And meanwhile, the positioning firmness is improved.