The present invention provides a hollow rotor structure for a direct-current motor and a winding structure of the same are provided for use in a direct-current motor. The hollow rotor structure includes a commutator, can output element, and a hollow rotor. The hollow rotor includes an iron core wound with a plurality of windings and is formed with an axial hole extending along the axial direction of the hollow rotor. Once mounted in a housing, the hollow rotor is spaced from a stator fixed in the housing and is separately connected to the commutator and the output element. When the commutator supplies a current to each winding, the hollow rotor generates the corresponding electromagnetic fields, which repel the magnets on the stator respectively. Thus, the hollow rotor generates a rotating force and outputs the rotating force through the output element.