<p>This study presents a novel offshore expandable HMFS system that integrates the functions of a floating breakwater and wave energy converters (WECs), offering an alternative approach to marine space development. A scaled experimental model was developed, consisting of hybrid functional modules, inter-module connectors, a mooring system, and integrated WEC units. The design incorporates WECs driven by parallel-axis gears and hinge connectors with linear torsional stiffness. The research experimentally examines the effects of connector stiffness, longitudinal spatial expansion, and mooring line fracture on key dynamic responses. The findings demonstrate that enhanced connector stiffness reduces module motion responses while increasing connector loads, providing experimental guidance for connector selection. The hinge-connected system demonstrates stable dynamic performance, while the rigid-connected system exhibits significant increases in pitch bending moment during longitudinal spatial expansion. Analysis of single mooring line fracture suggests avoiding systems with minimal mooring lines to prevent excessive planar displacement. These findings provide valuable experimental insights for the engineering implementation of the HMFS system.</p>