The migration of China's ship design software to domestic platforms becomes crucial for enhancing national innovation autonomy and reducing technological dependence against intensifying international competition. However, conventional domestic cross-platform strategies, such as system reconstruction or Browser/Server (B/S) architecture conversion, remain incompatible with ship design software. The domestically developed NuCAS system is examined to explore a new cross-platform migration strategy for message mechanisms applicable to shipbuilding industrial software. Through in-depth analysis of the technical framework and code structure of the message mechanism of the NuCAS system, multiple migration strategies are evaluated to innovatively proposed a migration strategy that rewrites the underlying core message mechanism of MFC (Microsoft Foundation Classes, a Windows API class library) based on the cross-platform Qt framework while preserving the upper-layer application code. This strategy successfully resolves the challenge of the seamless conversion of message mechanisms between MFC and Qt frameworks. The results demonstrate that the modified NuCAS system operates stably on domestic platforms, meeting the localization requirements of ship design software. It provides a groundbreaking approach for the cross-platform migration of message mechanisms in shipbuilding industrial software.