The invention discloses a floating pendulum-type wave power generation system with single cylinder acting in a full cycle. The floating pendulum-type wave power generation system comprises a double-acting hydraulic cylinder, a base, a floating body and two connecting rods, wherein the floating body is in a hollow sealed structure; one end of each connecting rod is welded to the floating body, and the other end of the corresponding connecting rod is hinged to a rear-end horizontal rod of the base, so that the floating body swings around supporting points along with the fluctuation of waves; one end with a rod, of the double-acting hydraulic cylinder, is hinged to the floating body; the other end without a rod, of the double-acting hydraulic cylinder, is hinged to a front-end horizontal rod of the base; and the piston rod of the double-acting hydraulic cylinder is driven by the swing of the floating body to stretch out and draw back, so that the mechanical energy of the swing of the floating body is converted into hydraulic energy, and the hydraulic energy is transmitted to an electric generator to generate electricity. According to the floating pendulum-type wave power generation system disclosed by the invention, through the design of mechanical transmission, wave energy can be stably absorbed, so that damage to a device, which is caused by the impact of great wave, can be avoided; and through the design of a hydraulic system, the purpose that single cylinder acts in full cycle can be realized, the acting time of wave energy can be doubled, energy output is stable, influences caused by the impact of the wave are reduced, and electricity generating quality is high. The floating pendulum-type wave power generation system is good in technical effect.