The invention relates to a rotor structure of brushless double-fed motor, which belongs to electrical machine. The rotor structure comprises a rotor shaft, a main iron core, a short-circuit loop additional iron core, a short-circuit loop isolation additional iron core, a rotor conductor, a conductor short-circuit end-ring and a common end-ring of the short-circuit loop of the rotor conductor, wherein the rotor shaft is positioned at the center of the rotor and penetrates through the rotor; the common end-ring of the short-circuit loop of the rotor conductor, the main iron core, the short-circuit loop additional iron core and the short-circuit loop isolation additional iron core are sequentially connected with each other; the main iron core, the short-circuit loop additional iron core, andthe short-circuit loop isolation additional iron core are all made of silicon steel sheets with a thickness of 0. 3 to 0.5 mm by lamination; the conductor short-circuit end-ring is positioned in a communication groove of the short-circuit loop additional iron core and is integrated with the rotor conductor; the rotor conductor with cylindrical shape is positioned in the rotor slot and penetrates through the rotor. The invention has the advantages that the motor rotor structure can simplify the rotor manufacture process of brushless double-fed motors, reduce the end leakage reactance of the rotor of brushless double-fed motors, improve the mechanical strength of the rotor and improve the insulating performance of the end-rings.