With the development of Waterproof Case, as the urban power and communication construction requires wires and cables, communication cables and signal cables to be buried in the ground, solutions for branching, connection, and waterproofing of cables are very important proposals. Plastic Waterproof Case has been successfully used abroad for more than 20 years, and it is also widely used in my country. Before 2000, most of the waterproof cases made of iron were used in our country; after 2000, my country's science and technology developed rapidly, and the plastic technology was gradually improved. Plastic Waterproof Cases gradually replaced metal Waterproof Cases with their low cost, good insulation and high degree of waterproofness. .