The flashover voltage of a FRP （Fiber-glass Reinforced Plastic） rod under the wet pollutant condition is lower than the rated voltage

so the flashover failure is unavoidable. The silicone rubber composite insulating rod （a FRP rod covered with silicone rubber sheds） increases the creepage distance to sa-tisfy the demands of the national standand GB3906. Its dry flashover voltage in-creases by nearly 20% and the pollution flashover voltage by more than 100%. It ensures the operation reliability of the insulating rod. More than 6 000 pieces of sili-cone rubber composite rods have been used on ZN12-10 vacuum circuit breakers with satisfactory results.