A wind turbine rotor with a vertical rotation axis connected to a hub having at least two horizontal supports, on the ends of which are tightly fixed blades, each consisting of two wings joined together, with a symmetrical or concavo-convex airfoil with the airfoil's chord lengths and thickness diminishing toward both wing ends. The rotor blade's upper and lower wings are radially deflected from the central zone outwards. The chord length of both wing ends and the chord length in the central zone are approximately inversely proportional to the radii of its location in relation to the axis of the rotor's rotation. The deflecting angle of the lower wing can be greater than the deflecting angle of the upper wing or the length of the lower wing can be greater than the length of the upper wing. These specifications provide uniform wind power consumption along the wing's length, increasing the efficiency of a wind turbine and its service life.