Small-size economical LED backlight source

The utility model discloses a small-size economical LED backlight source which comprises a bottom plate, supporting legs are arranged at the bottom of the bottom plate, a guide column is arranged on the upper end face of the bottom plate, a threaded hole is formed in the end of the guide column, and a cross-shaped hole penetrating through the bottom plate is formed in the bottom plate. The light guide plate is arranged on the upper end face of the bottom plate, first mounting holes are formed in the light guide plate, the guide columns are inserted into the first mounting holes in a one-to-onecorrespondence mode, lamp holder grooves are formed in one side face of the light guide plate, cross-shaped protrusions are arranged on the lower end face of the light guide plate, and the cross-shaped protrusions are higher than the guide columns; the light source is arranged on the light guide plate and comprises lamp beads and pins; the reflecting film is attached to the upper end face of thelight guide plate and cove