Abstract: The challenges posed by the harsh subsea environment and the demand for equipment safety, which necessitate highly reliable electronic modules, this paper proposed a high-reliability design method for a HIPPS subsea electronic module based on a dual-redundant architecture. The HSEM system consists of two subsystems forming a redundant configuration, with each subsystem comprising multiple types of boards such as the main control board, power supply board, and carrier board. Safety loops were identified in this study. Three optimization techniques were introduced: components redundancy, diagnostic coverage, and multi-level protection. After applying these optimizations, the failure rate was reduced from 464.1 FITs to 141.39 FITs, The system reliability has been significantly improved.