The invention discloses equipment for co-extruding three layers of cables and automatically adjusting the concentricity. The equipment comprises a first co-extruding machine, a second co-extruding machine, a third co-extruding machine and a machine barrel; a cable to be machined penetrates through the machine barrel; certain angles are formed among the first co-extruding machine, the second co-extruding machine and the third co-extruding machine, and the first co-extruding machine, the second co-extruding machine and the third co-extruding machine are mounted on the right side of the machine barrel; the first co-extruding machine, the second co-extruding machine and the third co-extruding machine are provided with a first adjusting bolt, a second adjusting bolt and a third adjusting bolt which are vertical to the axes of the first co-extruding machine, the second co-extruding machine and the third co-extruding machine respectively; a first gear, a second gear and a third gear are fixed at screwing ends of the first adjusting bolt, the second adjusting bolt and the third adjusting bolt respectively; and the first gear, the second gear and the third gear are connected with a motor through a transmission device, so that the adjusting bolts are controlled through controlling the rotation of the motor, and the concentricity of a plastic extruding machine is automatically adjusted, and furthermore, manpower is saved and the adjustment precision is improved.