In recent years, with the growing attention to offshore renewable energy, hybrid offshore renewable energy harvest system (HOREHS) has gradually emerged as a promising solution. These systems enable cost-effective harvest of offshore renewable energy and hold significant potential in contributing to the achievement of the United Nations Sustainable Development Goals. Since the concept remains at the early stage of development, there is a lack of systematic summary of challenges and latest development of these systems. This paper provides a comprehensive review of progress made in relation to this novel hybrid systems, including integrations approaches of diverse energy harvesting devices and various support technologies. The characteristics and limitations of different types of hybrid systems are compared and summarised. This paper then reviews the numerical simulations approaches and physical testing techniques for testing HOREHS and the mechanical responses of HOREHS obtained from these investigations, which demonstrate the feasibility of hybrid systems from the perspective of mechanical response. Finally, the paper outlines the potential challenges that HOREHS may face in the future.