The invention provides a grounding wire winder. The grounding wire winder comprises a first support bar set and a second support bar set; the first support bar set comprises a first vertical bar, a second vertical bar and a first cross bar used for connecting the first vertical bar with the second vertical bar, the second support bar set comprises a third vertical bar, a fourth vertical bar and a second cross bar used for connecting the third vertical bar with the fourth vertical bar, and the second cross bar and the first cross bar are rotatably connected; any one vertical bar of the first support bar set and any one vertical bar of the second support bar set are each provided with a cylinder body and/or a barrel body of which the opening direction is above the horizontal plane. The grounding wire winder further comprises a U-shaped positioning bar, and the two free ends of the U-shaped positioning bar are slidably matched with the cylinder body or drum body arranged on the first support bar set and the cylinder body or drum body arranged on the second support bar set respectively. The grounding wire winder can conveniently achieve unwinding of grounding wires after the grounding wires are wound and is used for solving the problem that an existing grounding wire winder is inconvenient for storing and remote carrying.