A light guiding structure, a backlight source and a display device are provided. The light guiding structure includes a light guiding plate, wherein at least one side end surface of the light guiding plate is provided with a fixing mechanism configured to fix a light bar. In the above-described light guiding structure, since the fixing mechanism provided on the side end surface of the light guiding plate is fixed to the light bar, the light guiding plate is accurately aligned with the light bar. The operation difficulty of fixing the light guiding plate to the light bar by the fixing mechanism is reduced, thus, it is easy to achieve the accurate alignment between the light guiding plate and the light bar.