The present invention discloses a suspended cable and overhead line fully insulated separation and combination device with a lightning arrester in the field of electrical equipment. The cable and overhead line fully insulated separation and combination device comprises a bottom frame and a knife. The top surface of the bottom frame is orderly provided with an upper pillar insulator, the lightning arrester and a lower pillar insulator. An upper contact is fixed at one side of the upper pillar insulator far from the lightning arrester. A bracket is fixed to one side of the upper pillar insulator close to the lightning arrester. The top surface of the lower pillar insulator is fixed to a fixed end of a lower contact, and a grounding rod for connecting a ground cable is fixed to the top surface of the free end of the lower contact. A stop block is fixed to the top surface of the fixed end of the lower contact. A pivot connection end of the knife is pivotally connected to the stop block. The free end of the knife can be clamped with the bracket and is in contact with an upper contact surface. The middle of the knife is provided with a contact piece which can be in insertion connection with a contact finger at the top surface of the lightning arrester.