Disclosed are a backlight module and a display device. The backlight module includes a plurality of lamp boards and a backplane. The backplane has a lamp board installation side. The lamp boards are spliced at the lamp board installation side to form a light-emitting area. A fastener is provided between two adjacent lamp boards and has a first end and an opposite second end. The first end has a first connecting structure, and two opposite sides of the second end are respectively provided with a first limit portion and a second limit portion. A second connecting structure corresponding to the first connecting structure is arranged on the lamp board installation side. The fastener is connected and fixed on the lamp board installation side through the first connecting structure and the second connecting structure. The first and second limit portions are respectively abutted against sides of the two adjacent lamp boards.