<p>The permanent magnet (PM) spherical motor, which is an innovative type of motor, is capable of providing three degrees of freedom of motion in a single joint, thereby minimizing undesirable inertia and friction associated with rotating components. However, in the face of model uncertainties and external disturbances, the trajectory tracking control of the PM spherical motor suffers from low tracking accuracy and poor robustness. To address these issues, a novel composite control approach is proposed in this paper. First, a rotor dynamic model of the PM spherical motor is derived to facilitate the controller design. Second, when the output trajectory is far from the desired trajectory, a sliding mode controller is designed to force the actual output trajectory of the PM spherical motor to quickly converge into the desired trajectory. Third, an extended state observer is designed to estimate and compensate for the external disturbances and model uncertainties in advance to achieve precise trajectory tracking control for the PM spherical motor when its actual trajectory is on the verge of the desired trajectory. Finally, the correctness and effectiveness of the proposed method are verified. Results indicate that the method proposed in this paper can achieve fast and accurate trajectory tracking, and has strong anti-interference capability.</p>