<p>Electromagnetic forming (EMF) technology, known for its high strain rate and non-contact characteristics, has been widely adopted to improve the formability and surface quality of lightweight alloys such as aluminum and magnesium. However, in conventional EMF of tubular components using single-coil configurations, the non-uniform distribution of electromagnetic force often results in axial deformation irregularities, typically manifesting as a “bulging center and tapered ends” profile. This non-uniform deformation restricts the achievable forming geometry and leads to excessive localized thinning. To address this issue, this paper proposes a novel inward-stepped magnetic field shaper (IMFS) featuring an inversely-stepped geometry—smaller on the coil side and larger on the tube side—to actively redistribute the electromagnetic force field and enhance the uniformity of tube deformation. The effectiveness of the proposed IMFS-assisted configuration is validated through both numerical simulations and experimental investigations. Experimental results demonstrate that, compared to conventional single-coil EMF, the IMFS structure improves axial deformation uniformity by more than threefold, significantly enhancing the final formed geometry. Furthermore, the study examines the influence of key electromagnetic parameters, including discharge voltage, on the deformation behavior of AA6061-O aluminum alloy tubes. The IMFS-assisted configuration also effectively mitigates wall thinning in the regions of maximum expansion. Overall, the results confirm that the proposed IMFS approach enables precise control of material flow and markedly improves deformation uniformity in electromagnetic tube forming.</p>