The utility model discloses a detection device for a red copper welding wire. Bottom plate, the top of the bottom plate is fixedly connected with a vertical block. A first sliding rail is fixedly connected to the top of the bottom plate and located on one side of the vertical block. One side of the vertical block is rotationally connected with a threaded rod through a bearing; the outer surface ofthe threaded rod is in threaded connection with a first sliding block; the bottom of the first sliding block is in sliding connection with the outer surface of a first sliding rail. The end, away from the vertical block, of the threaded rod is fixedly connected with a first handle, the top of the first sliding block is fixedly connected with a moving plate, and one side of the moving plate is sequentially and fixedly connected with a supporting plate and a second sliding rail from bottom to top. According to the detection device for the red copper welding wire, the flexibility of the weldingwire can be detected rapidly and conveniently, workers can conduct detection conveniently in the production process of the welding wire, time is saved, the detection efficiency is improved, and production of the welding wire is better guaranteed.