A cable connecting structure includes three three-phase power cable pairs respectively including a pair of power cables that are mutually connected, three insulating rubber connecting tubes covering connecting sections of the three three-phase power cable pairs, respectively, a steel pipe accommodating portions of each of the three three-phase power cable pairs, and the three rubber connecting tubes, and a heat dissipation material. The heat dissipation material is provided between the steel pipe and each of the three rubber connecting tubes, and makes contact with the steel pipe and each of the three rubber connecting tubes. The heat dissipation material includes a heat dissipating metal that has a melting point lower than a melting point of the steel pipe.