ABSTRACT Permanent magnet linear synchronous motors (PMLSMs) are widely used in high‐precision servo systems. However, the detent force negatively affects servo performance. To address this issue, a novel double‐sided PMLSM with closed‐secondary structure is proposed in this paper. The magnetic bridges with auxiliary windings are installed at both secondary core ends. The magnetic flux paths through bridges and primary end teeth influence end leakage flux. Therefore, the detent force is suppressed utilising this magnetic path. First, the compensation current in the auxiliary windings is designed based on detent force and back EMF in auxiliary windings. Affected by nonlinear factors, such as core saturation, significant detent force remains after applying compensation current. Thus, the compensation current is iteratively adjusted according to the residual detent force. When a staggered‐tooth design is applied to the primary core, the compensation current amplitude decreases, but the detent force can still be effectively suppressed. When the secondary core is extended to 30 pole pitches, the required compensation current increases due to diminished flux bridge influence. Nevertheless, FEM verification confirms that the suppression strategy maintains effectiveness. The prototype shows detent force reduction from 3.7 to 0.8 N with optimised compensation current. Experimental results verify the method's feasibility.