The present disclosure provides a light guide plate, a manufacturing method thereof, a backlight source and a display device. The light guide plate includes: a first surface, a second surface, and at least one blazed gating structure that is on the second surface of the light guide plate, wherein light incident from the first surface of the light guide plate forms a total reflection in the light guide plate after the light irradiates the at least one blazed gating structure and is diffracted by the at least one blazed grating structure.