The ship's medium-voltage DC integrated power system represents the future direction of maritime power systems and is a crucial foundation for implementing maritime power strategies. This study focuses on optimizing the grounding resistance values within these systems. It establishes a comprehensive optimization model that considers both the sensitivity and safety of grounding protection. Key parameters include fault-to-ground current and grounding resistance overcurrent limits. The optimization aims to reduce the operational costs associated with grounding resistors while ensuring optimal resistance values. Combined with specific parameters, a modeling analysis of the ship's integrated power system in which a ground fault actually occurred was carried out. When a ground fault occurred, the constraints considered were as follows: (1) Ground current constraints at the fault point; (2) Ensure that the characteristic electrical quantity is significant Sensitivity constraints; (3) Ground resistance fault overcurrent constraints to ensure the safety of personnel and equipment. According to the constraint conditions, after determining the resistance optimization range, the optimization function is evaluated piecewise, and then the optimal grounding resistance value is selected.