In order to improve the properties of mica paper, aramid fiber and PVA fiber were employed in mica paper as additive. Aramid fiber can act as skeleton and improve the dielectric strength of mica paper greatly accordingly at the optimum dosages of aramid fiber, 4%. When 3% of PVA fibers were added the tensile strength of mica paper increased significantly. It is because PVA fibers can smelt and act as bond for mica flake and aramid fiber under high temperature. The optimum beating degree of aramid fiber was 35 oSR, and the optimum drying temperature was 100°C. Compared with traditional mica paper, dielectric strength of composite mica paper with aramid fiber and PVA fiber increased above 25% and tensile strength increased 2.30 times under this optimum condition. In addition, the insulation performance of composite mica paper also improved substantially.