Electrodynamic suspension (EDS) with a linear permanent magnet Halbach array, which can be used in ultrahigh-speed maglev systems, has gained increasing attention in recent years. However, inefficient calculation methods of electromagnetic forces restrict the stability research of EDS systems. Hence, an efficient 3D analytical model of the electromagnetic force is established in the paper based on an improved analytical model of the source magnetic field excited by the Halbach array, and then the application conditions of the model are studied. Finally, the analytical results are compared with the experimental results, which are provided by the experiments carried out on a high-speed rotating experiment platform with a flywheel. The results show that the proposed model can shorten the computation time of electromagnetic force to less than 10 ms and the relative errors of analytical results are around 5% under the conditions ①wp/τ≥2.5, wd/wp≥1.5 or ②wp/τ≥4, wd/wp≥1 (τ is the pole pitch of the Halbach array, wp is the width of the permanent magnet, wd is the width of the conducting plate). The analytical model meets the engineering requirements and can provide a reference for further stability research and experiments on EDS systems.