Ocean wave energy is a widely anticipated new type of renewable energy. However, due to the ultra-low-frequency and random motion characteristics of ocean waves, effectively harnessing it presents a significant challenge. This paper proposes a Mag-Boost mechanism based on the phenomenon that the magnetic torque undergoes a sudden change when the magnetic poles of two magnets are orthogonal. This innovative mechanism, requiring just a trigger below 1 Hz, can stimulate a power-magnet to generate high-frequency oscillation without direct contact. Utilizing this mechanism, a high-power wave energy harvester (WEH) with ultra-low-frequency response capabilities has been developed. Tested on a six-degree-of-freedom platform, the WEH demonstrated a high-output power of 1.44W and a power density of 1.2 kW/m3 at a frequency of 1 Hz and an inclination angle of 30°. The peak open-circuit voltage of the WEH reached 5 V, ensuring a completely independent and stable power supply for wireless temperature and humidity sensors. Furthermore, the Mag-Boost mechanism also shows considerable potential for harvesting other forms of low-frequency environmental energy, including wind, vibration, and human kinetic energy.