Laser-driven capacitor-coil (LDC) targets provide an effective approach for generating pulsed magnetic fields at the hundreds-of-tesla level in laboratory experiments, with broad applications in high-energy-density physics (HEDP). However, during intense laser–target interactions, self-generated magnetic fields arising from hot-electron transport, charge separation, and laser–plasma instabilities can significantly overlap, both temporally and spatially, with the magnetic field produced by the coil current. This overlap leads to systematic overestimation and ambiguity in magnetic-field measurements based on B-dot probes. To address this issue, a series of comparative experiments were designed and performed on the Shenguang-II laser facility. Under identical laser-driving and diagnostic conditions, three types of targets—insulated targets, simple coil targets, and inflected coil targets—were irradiated. By systematically comparing the time-resolved magnetic signals measured at the same probe location, the contribution of self-generated magnetic fields was experimentally separated from the total signal and quantitatively evaluated. Based on this approach, an experimentally implementable subtraction method was proposed to remove the self-generated magnetic-field component without relying on numerical simulations. Furthermore, combined with an axial magnetic-field decay model based on a finite-length solenoid approximation, the coil current and the magnetic field at the coil center were reconstructed. The results show that, after subtracting the self-generated magnetic field, the extracted peak magnetic field reaches several hundred tesla, with a more physically reasonable energy conversion efficiency. The method also reveals distinct temporal evolution features of different coil configurations, providing deeper insight into magnetic-field generation and transport processes. This work establishes a practical and reliable experimental methodology for decoupling overlapping magnetic-field components, significantly improving the accuracy of pulsed magnetic-field diagnostics. It offers a new pathway for precision magnetic-field measurements in magnetized indirect-drive inertial confinement fusion and HEDP studies.