The present disclosure relates to a light guide plate and its fabricating method, as well as a backlight module. The light guide plate comprises a light-transmitting plate body provided with a plurality of light guide dots on a light-exiting surface thereof, and further provided with a plurality of dimming pits, wherein a plurality of light guide dots are provided around each of the dimming pits; an inner wall of each of the dimming pits sequentially includes multiple levels of dimming surfaces along a depth direction of the dimming pits, for reflecting light incident thereon to the light guide dots. The backlight module comprises the light guide plate provided in the above-described technical solution.