Carbon nanotubes used as field emitters, the field emission display with improved insulator was reported. The fabrication process of improved gate structure with the mica plate as insulator between gate-electrode and cathode was presented. The technical development in the design of the improved insulator was also given. The patterned silver slurry was used to form the gate electrode and the screen-printed insulation slurry was formed the gate cover layer. The sealed field emission display packaged by the vacuum-device process had been developed and demonstrated. The modulation of electron emission by the gate voltage was also confirmed. The whole flat display device possessed better field emission properties and high brightness.