Through reasonable structure design, this work made the blades that make up the impeller of turbine automatically opened and closed under the force of ocean current, realizing the capture of ocean current energy in different directions, which greatly improved the power generation efficiency of the turbine. The design of this turbine breaks the traditional integral single-blade design idea, divides the traditional integral blade that constitutes the large impeller into a series of sub-blades and solves the contradiction of the opposite torque caused by the water flow in the left and right blades during the rotation of the impeller. The control system composed of the fan-shaped angle control grooves and the gravity-tilted rotors realized the automatic opening and closing of the blades under the force of ocean current. The blades were designed into fish-shape based on the principle of fluid dynamics to reduce the water flow resistance. The physical model test and numerical simulation of the power generation efficiency of the device were carried out to verify the feasibility of the design model. And the results showed that the energy utilization efficiency of the new vertical-axis ocean current turbine was higher than that of the traditional single-blade turbine.