The present invention discloses a light emitting diode (LED) backlight device and LED display device, including a plurality of backlight partitions; a reflective material layer covering a surface of the backlight substrate; a plurality of metal traces disposed within the backlight partitions and disposed between the backlight substrate and the reflective material layer; a plurality of pad openings penetrating from a surface of the reflective material layer to a surface of the metal traces. An orthographic projection of the pad openings projected toward the backlight substrate is completely within an area of the metal traces; and a plurality of solder paste application regions located in the pad openings. The LED display device assembled by the LED backlight device according to the present invention improves the yield of solder paste printing and die bonding, improves the light reflection, reduces the loss of light energy, and improves the light efficiency.