<p>Induction heating is an effective way to improve gear performance. Reasonable designs of the induction coil structure are crucial to achieve uniform tooth surface heating. The objective of this paper is to investigate the feasibility of applying 3D-printed coils to induction heating. To this end, a variable section coil (VC) was designed and fabricated using Selective Laser Melting (SLM) technology. The magnetic field distribution and heating effects of the VC and equal section coil (EC) were compared and analyzed using finite element simulation. The induction heating experimental system validated the feasibility of variable section coils for practical applications. In contrast to the equal section coil designs adopted in prior research, this study integrates variable section profiling coils with 3D printing technology to investigate the heating performance of spiral bevel gears with complex geometric features, thereby achieving concurrent improvements in both heating uniformity and efficiency. The paper’s results indicate that, compared to the conventional equal section coil, the variable section coil enhances the temperature uniformity of the gear surface by 38.24% and the heating rate by 27.27% during the heating process, enabling the gears to reach austenitization temperature in a shorter time. The accuracy of the numerical model is further confirmed through the comparative analysis of experimental and simulation results. This research offers a novel approach to the induction heating of complex geometrical workpieces and presents an effective method to optimize the gear induction heating process.</p>