The needle type ordinary ceramic insulator porcelain and cast steel are glued together with cement glue, and the surface of the porcelain piece is coated with a layer of glaze to improve the insulation performance of the insulator. The surface of the cast steel and porcelain glue is coated with a moisture-proof agent.

The main reason that overhead lines are vulnerable to lightning strikes and dirty flashovers is that the needle insulators of the line are contaminated and dampened by rain, and the insulation level is lowered, causing line faults due to pollution flashover and breakdown.

After the crack or severe hardening of the needle type ordinary ceramic insulator, it can continue to run in fine weather. However, in the case of light rain or heavy fog, the insulation drops sharply, causing line failure.

In addition, when a pin-type ordinary ceramic insulator is slightly cracked, it is difficult to find the defect even if the line patrol person holds the telescope, which leaves a safety hazard to the line and increases the unsafe factor of the line operation.