(b) Provided is an overhead insulated wire over-voltage protection device with dual protection and protection method thereof. As in recent years, the national urban and rural electric network is massively reconstructed, more and more urban distribution networks massively employ overhead insulated wires, direct stroke lightning over-voltage or induced over-voltage caused by lightning stroking the overhead insulated wires is prone to leading flashover or breakdown of insulators. An overhead insulated wire over-voltage protection device with dual protection comprises insulated wires ((/b)(b)1(/b)(b)), the insulated wires are connected with insulators ((/b)(b)2(/b)(b)), the insulators are respectively connected with electric current guide rings ((/b)(b)6(/b)(b)) and cross arms ((/b)(b)7(/b)(b)); the cross arms are connected with connection abutment plates ((/b)(b)8(/b)(b)), the connection abutment plates are connected with electric current limiting members ((/b)(b)5(/b)(b)), the electric current limiting members are connected with electric current guide balls ((/b)(b)4(/b)(b)) of the electric current limiting members; and the electric guide balls of the electric current limiting members are connected with electric current guide balls ((/b)(b)3(/b)(b)) of the wires. The overhead insulated wire over-voltage protection device with dual protection and protection method thereof are applied to over-voltage protection of overhead insulated wires. (/b).