At present, the main evaluation standard for the waterproof performance of deep water electrical connectors is based on the IP waterproof rating standard. To see how the waterproof performance of the deep water electrical connector is, it mainly depends on the last two digits of IPXX, XX, D and X are from 0 to 6, and the highest level of Z is 6; the second number is from 0 to 8, and the highest level of Z is 8. ; So the highest waterproof rating of the deep water electrical connector is IP68. Molded cable accessories are mainly used on 35kv and above cross-linked cable straight-through waterproof joints. It uses radiation cross-linked or chemically cross-linked polyethylene film tape to wrap around the treated cable joint, press it with the help of a special mold (aluminum mold or heat-resistant tension tape), and heat the formed joint . In the production process, the irradiated cross-linked polyethylene tape is pre-stretched (stretched by 30% at 100c, then cooled and cut into coils), wrapped into a joint, and then heated and retracted to make the wrapped tape. The air gap between layers is compressed, thereby increasing the discharge voltage of the air gap. This type of joint has a high level of partial discharge and is suitable for making cable joints with higher voltage levels.