Wire core insulation lock is used to solve the problem of inconvenient wire core insulation protection when the secondary circuit is disconnected. It includes a first shell, a second shell, an inflation and deflation assembly, an inner membrane, a seal and bolts. The first shell includes a first wire core splint, a first marker splint, and a second wire core that are sequentially arranged and connected to each other. The splint and the first wire splint, the second shell includes a third wire core splint, a second marker number splint, a fourth wire core splint and the second wire splint that are arranged in sequence and connected to each other, and the first wire splint and the second wire splint The connecting ends are hingedly connected; semicircular seals and fixing parts are respectively provided on the inner walls of the first, second, third and fourth wire core splints, and an inner film is provided between the first and second wire core splints, A closed air chamber is formed between the inner membrane and the first marker splint, and an inflation and deflation assembly is arranged on the first marker splint. The insulation lock can effectively realize the insulation protection of the wire core, and can be reused.