The liquid pump driven by a bearingless permanent magnet slice motor has higher requirements on the motor suspension performance in a complex fluid load environment. Aimed at the problems that the motor model is difficult to obtain accurately and the complex fluid load affects the motor suspension performance, an improved control strategy for the rotor radial suspension performance based on electromagnetic force modeling and disturbance compensation is proposed. First, based on the Maxwell tensor method, an analytical model of rotor radial suspension force including active suspension force component and eccentric magnetic tension component is established. Second, the unmodelled part is observed by a linear extended state observer. Third, from the aspect of compensating the eccentric magnetic tension and compensating the unmodeled part, the suspension winding current is reconstructed, and the corresponding suspension control subsystem is constructed. Finally, the effectiveness of the proposed control strategy was verified by experimental results.