The invention provides a power cable moving speed measuring device. The power cable moving speed measuring device comprises a horizontal rail, clamping sliding blocks, a bidirectional lead screw, cable rolling shafts and a micro calculator, wherein a sliding groove is formed in the horizontal rail, a pair of the clamping sliding blocks are symmetrically distributed on the horizontal rail; the clamping slide blocks are slidably connected with the horizontal rail, rotating cylinders are arranged on the clamping sliding blocks, and the two rotating cylinders are oppositely arranged and are in rotating contact with a cable; the bidirectional lead screw extends into the sliding groove to connect the two clamping sliding blocks; the tail end of the bidirectional lead screw is further connected with an adjusting handle, and the two clamping sliding blocks are driven by rotation of the adjusting handle to move on the horizontal rail and get close to or away from each other; the two cable rollers are arranged on the front side and the rear side of the horizontal rail respectively; and the micro calculator is connected with the rotating cylinders. According to the power cable moving speed measuring device, the moving speed of the cable can be precisely and rapidly measured, and a reference is provided for power cable cleaning, insulating paint spraying and cable drying.