This paper proposes an internal inspection system based on electromagnetic coupling sensing and permanent magnet magnetization, providing a theoretical study on alternating magnetic field induction and magnetic flux leakage coupling technology. Simulation analysis and experimental validation were conducted to evaluate the feasibility and reliability of the proposed magnetic rope system (MRS). Through research it has been found that a novel magnetic ring structure has been demonstrated to generate an axial magnetic leakage field and a circumferential uniform alternating electromagnetic field. The excitation method combining electromagnetic coupling sensing with permanent magnets enhances wall penetration capability and magnetic flux intensity, enabling the identification of subsurface defects and shallow surface defects. The amplitude of magnetic field intensity fluctuations of surface defect detection can reach 0.011 T, which is only 0.008 T compared to the test results of subsurface defects. By comparison, the amplitude of fluctuation for the probe structure using permanent magnets alone is only 0.002 T. The combined configuration of MRS and magnets optimizes defect detection rate and sensitivity, making it suitable for complex internal inspection environments and enhancing the reliability and stability. The sensitivity range of detection technology without using permanent magnets is between 0.24 and 0.36. The use of permanent magnets can increase sensitivity to 0.41∼0.77. The defects have lower sensitivity caused by the complex metal environment, and the use of permanent magnet technology can increase sensitivity by more than 0.3. The MRS overcomes the limitations of single-technology approaches in detecting multiple types of defects, thereby improving the detection capability for both near-surface and deeply buried defects.