Backlight module, light guide plate thereof and display device applying backlight module

Provided in the invention is a backlight module comprising a light guide plate which is provided with an upper surface, a lower surface and a dimming structure located on the lower surface, an opticalsheet arranged opposite to the upper surface of the light guide plate, and a light source adjacent to light guide plate. Light emitted by the light source has first brightness distribution in a firstdirection after passing through the light guide plate; the first brightness distribution has first maximum brightness and second maximum brightness; the first maximum brightness corresponds to a first angle and the second maximum brightness corresponds to a second angle; the angle absolute value of the first angle and the angle absolute value of the second angle are larger than 60 degrees respectively; and the absolute value of the difference between the first maximum brightness and the second maximum brightness is smaller than or equal to 30% of the first maximum brightness. 一种背光模块，包括一导光板，具有一上表面、一下表面及位于下表面的调光结构；一光学片，