In high-voltage transmission systems, the core function of insulators is to achieve insulation isolation between conductors and towers, and glass insulators have particularly prominent advantages in this field, first reflected in their excellent insulation performance. The dielectric loss value (a key indicator to measure the loss of insulating materials) of glass insulators is extremely low, usually less than 0.001, far lower than 0.005 of ceramic insulators. This means that during long-term operation, their power loss is smaller, and it is not easy to increase leakage current due to insulation aging. Even in humid environments with humidity above 90% or hazy weather, the water film formed on the surface of glass insulators is not easy to conduct electricity, which can effectively avoid "surface flashover" accidents (i.e., current breakdown along the insulator surface) and ensure the normal power supply of transmission lines in severe weather.​

Super weather resistance is another core advantage of glass insulators. The special hard glass material used can withstand extreme temperature differences from -40℃ to 80℃. In winter in cold regions, the glass material will not crack due to freeze-thaw cycles; in southern regions with high temperature and humidity, it can also resist mold growth and acid rain erosion. Tests show that after soaking glass insulators in a simulated acid rain environment with a pH value of 2.5 for 1000 hours, there is no corrosion trace on the surface, and the insulation performance only decreases by 0.5%, far better than the 10% performance attenuation rate of ceramic insulators. In addition, glass insulators also have excellent resistance to UV aging. When exposed to strong UV environments (such as plateau areas) for a long time, the material will not become brittle or discolored, and the service life can reach more than 30 years, which is 1.5 times that of traditional ceramic insulators.​

Stable mechanical strength and easy maintainability further enhance the practical value of glass insulators. Its tensile strength can reach more than 80MPa, which can bear the conductor weight, wind load and ice load of transmission lines, and can still maintain structural integrity under the condition of level 12 typhoons or 20mm ice coating. More importantly, glass insulators have "self-breaking property" — when there are hidden defects (such as tiny cracks) inside, they will break automatically under the action of mechanical stress and electric field. Operation and maintenance personnel can quickly identify and replace them with the naked eye, without the need for complicated detection one by one, which greatly reduces operation and maintenance costs and workload. In contrast, the hidden defects of ceramic insulators are difficult to find, and they are prone to line outage accidents due to sudden fracture.​

It is these core advantages that make the application proportion of glass insulators in global high-voltage and ultra-high-voltage (UHV) transmission lines continue to increase. Especially in extreme climate regions (such as plateaus, coastal areas, and deserts), they have become the "backbone" to ensure the safe and stable operation of power grids.