The present invention provides a side-edge backlight module, which includes a backplane, a backlight source arranged inside the backplane, and a light guide plate arranged inside the backplane. The backplane includes a main body and a bracket connected to the main body. The main body is made of a plastic material and the bracket is made of a metal material. The backlight source is mounted to the bracket. The side-edge backlight module of the present invention adopts a backplane that is composed of a plastic main body and a metal bracket and this helps making the side-edge backlight module light-weighted provides multiple choices of the raw materials. Further, the main body directly forms a reflection surface by which the use of an additional reflector plate is eliminated, so that the installation of a light guide plate is made easy and the manufacture cost is further reduced.