Wire tightener for pipeline welding ground wire and application of wire tightener

The invention relates to a wire tightener for a pipeline welding ground wire and application of the wire tightener. The wire tightener comprises a support plate; a rigging screw vertically penetrates through the support plate and is in threaded connection with the support plate; a compressing sheet is arranged at the end of the rigging screw; one end of the support plate is fixedly connected with a compressing support; a compressing screw penetrates through the compressing support, and the rear end of the compressing screw supports against a compressing baffle; the compressing baffle can slide on the compressing support in a reciprocating manner; a clearance is reserved between the compressing baffle and the support plate; one end of a copper braided wire is fixed at one end, away from the compressing support, of the support plate; the other end of the copper braided wire bypasses a pipeline in the circumferential direction of the pipeline and then penetrates out of the clearance; the compressing sheet is loc