Diffusion plate module, backlight source and display device

The invention provides a diffusion plate module. The diffusion plate module comprises a first diffusion plate and a second diffusion plate positioned below the first diffusion plate, and a gap is formed between the first diffusion plate and the second diffusion plate. Correspondingly, the invention further provides a backlight source comprising the diffusion plate module and a display device comprising the backlight source. Compared with the prior art, the diffusion plate module has the advantages that light rays of a light source can be more uniformly irradiated on a display panel, and the backlight source and the display device can be thinned.