Abstract: To address the issue of conducted emission exceeding standards in the electromagnetic compatibility testing of subsea electronic module board systems and ensure the reliable operation of HIPPS (high integrity pressure protection system), tests were conducted on the power ports in accordance with standards including IEC 61000-6-2, API 17F, and CISPR 32. Through step-by-step investigation and comparative experiments, interference sources were identified, and the effectiveness of corrective measures was verified. Ultimately, an integrated solution combining fourth-stage filtering at the power input end and magnetic rings at the output end was adopted, successfully reducing all conducted emission values below the standard limits with a margin exceeding 10 dB. The study demonstrates that proper filter integration effectively suppresses low-frequency disturbances, while magnetic rings significantly attenuate high-frequency noise. This comprehensive solution successfully resolves the conducted emission issues in subsea electronic module board systems, providing valuable practical engineering basis and theoretical reference for the electromagnetic compatibility design and analysis of high-reliability subsea electronic equipment.