A backlight source and a display device are disclosed. The backlight source includes a frame, an optical film sheet, a light guiding plate and an embedded block. The coefficient of volume expansion of the embedded block is greater than the coefficient of volume expansion of the frame; the frame has a first transverse protrusion formed at a side in proximity to a light guiding plate, a bottom surface of the first transverse protrusion is attached to the light guiding plate by pressing, and the bottom surface has a groove provided therein, in which the embedded block is arranged.