绝缘子的主要功能是实现电气绝缘和机械固定，为此规定有各种电气和机械性能的要求。如在规定的运行电压、雷电过电压及内部过电压作用下，不发生击穿或沿表面闪络；在规定的长期和短时的机械负荷作用下，不产生破坏和损坏；在规定的机、电负荷和各种环境条件下长期运行以后， 不产生明显的劣化；绝缘子的金具，在运行电压下不产生明显的电晕放电现象，以免干扰无线电或电视的接收。
The main function of insulator is to realize electrical insulation and mechanical fixation, so there are various electrical and mechanical performance requirements. For example, under the action of specified operating voltage, lightning overvoltage and internal overvoltage, no breakdown or flashover occurs along the surface; under the action of specified long-term and short-term mechanical load, no damage and damage occurs; after long-term operation under the specified mechanical and electrical load and various environmental conditions, no obvious deterioration occurs; insulator fittings do not produce obvious deterioration under the operating voltage Corona discharge to avoid interference with radio or television reception.
因为绝缘子是大量使用的器件，对其连接金具还要求具有互换性。此外， 绝缘子的技术标准还根据型号和使用条件的不同，要求对绝缘子进行各种电气的、机械的、物理的以及环境条件变化的试验， 以检验其性能和质量。
Because insulators are widely used devices, their connecting hardware is also required to have interchangeability. In addition, according to the different models and service conditions, the technical standards of insulators require various electrical, mechanical, physical and environmental conditions change tests to test the performance and quality of insulators.