Backlight module, manufacturing method thereof, and display device and illuminating device comprising the same

A method of manufacturing a backlight module, comprising:

• fixing a light source on a back plate;
• forming a first light reflecting structure on at least one side surface of a light guide plate, the at least one side surface of the light guide plate being located between a first surface and a second surface of the light guide plate opposed to each other and having an acute angle with respect to the first surface of the light guide plate;
• and
• fixing the light guide plate on the back plate, such that the light source is located at a side of the light guide plate with the first surface, and the orthographic projection of the light source on the first surface is at an edge portion of the first surface of the light guide plate that is adjacent to the side surface, and the light emitted from the light source is at least partially reflected by the first light reflecting structure after entering the light guide plate through the first surface of the light guide plate.