The invention relates to a tidal current energy power generation device, in particular to a vertical shaft tidal current energy power generation device. The vertical shaft tidal current energy power generation device comprises an auxiliary starting water turbine, a connecting block, a main water turbine, a rotating shaft, a first bevel gear, a control cabinet, a second bevel gear, a generator, a connecting and disconnecting device and the like. When the seawater flow speed is low, a resistance-type auxiliary starting water turbine auxiliary starts a lifting-type main water turbine, so that themain water turbine rotates even when the seawater flow speed is low, and the overall power generation output is improved; when the seawater flow speed is high, the resistance-type auxiliary startingwater turbine and the lifting-type main water turbine independently operate without dragging the lifting-type main water turbine, and the main water turbine independently drives the rotating shaft torotate to generate electricity, so that the power generation output is greatly improved; and the main water turbine adopts a double-layer blade with an end plate, the end plate can effectively restrain vortex at the end portion of the blade and improve power output, the torque of the double-layer blade is larger than the torque of a single-layer blade, and the power is higher.