Shielded cable is a cable with the ability to resist external electromagnetic interference formed by adding a shielding layer to the transmission cable. The shielding layer of this type of cable is mostly woven into a mesh of metal wires or metal films, and there are many different ways of single shielding and multiple shielding. Single shielding refers to a single shielding mesh or film that can wrap one or more wires. The multiple shielding method refers to multiple shielding nets, and the shielding film is located in a single cable. Some are used to isolate electromagnetic interference between conductors, and some are double-layer shields used to enhance the shielding effect. The mechanism of shielding is to ground the shielding layer to isolate the induced interference voltage from the external conductor.