Based on the Meissner effect a superconducting hollow sphere rotor is levitated in the vacuum housing. During the high speed rotation, the dynamic deformations caused by the centrifugal force and the temperature variation will generate magnetic disturbing torque on the superconducting rotor. The deformations of the rotor are analyzed and simulated by finite element method, and the deformation laws are obtained. According to the results, an analytical model is presented to calculate the magnetic suspension disturbing torque due to the dynamic deformations. A case study is given to discuss the disturbing torque and the drift error. It has significant theoretical value for the design and optimization of the rotor structure.