The invention discloses a photoelectric composite cable for a 5G base station, which comprises an outer sheath, a shielding layer, an insulating layer and a central reinforcing core, wherein the outersheath wraps the insulating layer; a plurality of optical cables and power lines are arranged between the insulating layer and the central reinforcing core; the optical cables and the power lines arearranged around the central reinforcing core; the optical cable comprises a loose tube and a light-guide fiber wrapped in the loose tube; the insulating layer comprises an insulating inner layer andan insulating outer layer; external thread is arranged on the outer surface of the insulating inner layer; internal thread is arranged on the inner surface of the insulating outer layer; the thread pitches of the external thread and the internal thread are different; crests of the external thread abut against crests of the internal thread; and a cavity extending in the length direction of the composite cable is formed between the external thread and the internal thread. The photoelectric composite cable is reasonable in design, and the cavity extending along the length direction of the composite cable is formed in the insulating layer, so that the dielectric constant of the insulating layer can be effectively reduced, the dielectric loss is reduced, and the transmission efficiency of the photoelectric composite cable is remarkably improved.