The invention discloses a cable attaching device for uniformly distributing copper wires in a cable shielding layer by using magnetic attraction. The device comprises: a cable strip, a protective frame, a movable wire covering device, a wire aligner, and copper wires. The protective frame is arranged on the left end surface of the movable wire covering device. The copper wires are fixedly connected with the movable wire covering device. A mounting base is displaced on fixed columns of different lengths by an electromagnet through magnetic attraction, such that a head wheel frame changes of thesizes of the copper wires for covering different sizes of cables with wires. Finally a weaving operation is performed by a movable plate at the front end. The pressing force for the copper wire weaving is increased by different rotation directions on both sides of a gear. Thus, the copper wires are more stable. A friction wheel matches the rolling of a matching wheel, and the friction is increased by an irregular skin layer on the friction wheel so as to advance the copper wires. Further, the bending of the wire is pulled by the three-position limit of a curved block, so that the copper wiresabove can be better input to the cable.