The continuity and reliability of shipboard power systems are critical for their safe operation. Traditional protection strategies struggle with sensitivity and selectivity issues, particularly in multi-generator setups handling various short-circuit faults. This paper introduces an adaptive overcurrent protection strategy based on a composite voltage criterion to address these challenges for turbine and diesel generators under different operating conditions. The strategy incorporates a composite voltage criterion, combining inter-phase undervoltage and negative-sequence voltage elements, to enhance fault detection sensitivity and selectivity beyond the current criterion. A hardware-in-the-loop (HIL) simulation system based on RTLAB was developed to validate this strategy. The results show that the proposed approach can rapidly differentiate between short-circuit fault types, effectively avoid maloperation, and ensure the stability and continuity of the shipboard power system.