The invention relates to a multi-section vane for an ocean current energy power generation device. The multi-section vane for the ocean current energy power generation device comprises an impeller rotary shaft, a first-section vane, a second-section vane, a third-section vane, a first hinge, a second hinge, a first magnetic material, a second magnetic material, a third magnetic material and a fourth magnetic material. The multi-section vane for the ocean current energy power generation device is characterized in that the first-section vane of the multi-section vane is connected with the impeller rotary shaft; the second-section vane is connected with the first-section vane through the first hinge and the first magnetic material; the third-section vane is connected with the second-section vane through the second hinge and the second magnetic material; the first hinge and the second hinge are installed on the two opposite surfaces of the vane respectively; the magnetism of the second magnetic material is far higher than that of the first magnetic material. The multi-section vane for the ocean current energy power generation device is higher in power generation efficiency, can bear strong ocean current impact and is higher in cutting-out velocity.