The invention relates to a photovoltaic power and power supply network power alternately powered offshore floating charging pile beside a wharf, and belongs to the technical field of application of charging piles. A power supply board is arranged on the middle part of the wharf, a second power distribution room and a power supply network are arranged on the right side of the power supply board, a first power distribution room, an inverter, a controller and a solar cell are arranged on the left side of the power supply board. The offshore floating charging pile is powered by current generated by the solar cell illuminated by the sun through a conductor wire, the controller, the inverter, the first power distribution room and the power supply board. The offshore floating charging pile is powered by current output from the power supply network through the conductor wire, the second power distribution room and the power supply board. When an electrode strap and a first alternate electrode are rotated to switch on a circuit, the offshore floating charging pile is powered by a photovoltaic component, and when the electrode strap and a second alternate electrode are rotated to switch on the circuit, the offshore floating charging pile is powered by the power supply network. The offshore floating charging pile can be driven by a first buoy and an intelligent navigation system, which are arranged on the left side of the offshore floating charging pile, to move on the water.