Ocean wave energy, which is much rich on the earth, is one of the highest density energy among all renewable energies such as wind and solar energy. However, traditional ocean energy harvesters are unpractical because of their complicated conversion structures, low transmission efficiency，and weak anti-corrosion and anti-shock capacities. Thus, a wave energy harvesting device for promoting the tran-sferring efficiency, reliability and stability, which is called direct energy harvester, is more and more emphasized and has become a research focus. This paper summarizes in detail the research status, characteristics, main classes, charging control strategies and power management systems of direct ocean wave harvesters. Moreover, the development tendencies of direct ocean wave harvesters are prospected.