The invention relates to the technical field of driving motors, in particular to a rotor structure, a motor and a refrigeration device. The rotor structure includes an inner rotor core, a fixed part and an outer rotor core. The inner rotor core has a limit hole which runs through the inner rotor core along the axis of the inner rotor core. The fixed part includes a top cover, an inserting block and a bottom cover. The inserting block is fixedly connected with the top cover. The inserting block is inserted into the limit hole so as to be in limit fit with the inner rotor core in the circumferential direction of the inner rotor core. The inserting block is also in limit fit with the bottom cover in the axial direction of the inner rotor core. The outer rotor core sleeves the inner rotor core. The top cover and the bottom cover are respectively located on two opposite sides of the outer rotor core respectively along the axis of the inner rotor core, and are in limit fit with the outer rotor core in the axial and circumferential directions of the inner rotor core respectively. In the working process of the rotor structure provided by the invention, dislocation and detachment between the inner rotor core and the outer rotor core cannot occur easily. Accordingly, the safety performance of the motor formed by adopting the rotor structure is relatively high.