A field emission illumination device includes a sealed tubular body, an anode layer, a fluorescence layer and an electron emitting cathode electrode. The sealed tubular body has a light-permeable portion and the anode is formed on an inner surface of the light-permeable portion of the tubular body. The fluorescence layer is formed on the anode layer. The electron emitting cathode is positioned in the tubular body and includes at least one carbon nanotube yarn. In the illuminating process the energy in the field emission illumination device only undergoes transformation from electric energy to luminous energy, so the efficiency of the energy transformation is increased.