In the current context of the dual-carbon policy, the national demand for clean energy, such as hydrogen, is growing significantly. Serpentinization of peridotite is one of the most widespread water-rock interactions on the seafloor, and hydrogen gas, a primary product of this process, serves as a crucial pathway for the formation of marine hydrogen energy. Therefore, the deep oceanic crust holds highly promising hydrogen energy reserves, representing a vital breakthrough for alleviating current dual-carbon pressures and driving the development of new productive capacities. However, global technologies for detecting and extracting marine hydrogen energy are still in their infancy, presenting a significant opportunity for future seafloor energy exploration and growth. This paper systematically reviews the formation principles and distribution characteristics of marine hydrogen energy, outlining potential detection technologies and extraction methods. We propose that comprehensive geophysical exploration methods, such as multibeam bathymetry, magnetic surveys, gravity measurements, and multi-component seismic exploration, hold promise for detecting potential hydrogen reservoirs on the seafloor. Additionally, methods like hydraulic fracturing and microwave heating could be utilized for extracting hydrogen from these reservoirs. However, due to the limited understanding of marine hydrogen energy and the unique challenges associated with hydrogen storage and transport, there is a pressing need to develop specialized detection and extraction technologies tailored to marine hydrogen energy. Advance layout in this direction will provide the necessary technical support for the exploitation and utilization of marine hydrogen energy and spur revolutionary breakthroughs in various technological fields.