A vertical axis wind turbine includes a support axis and a wind wheel. The wind wheel includes a rotation base, plural rotation stand sets, plural deflection structures, plural blades, and plural deflection-limiting structures corresponding to the plural blades. The rotation base is rotatably disposed on the support axis. The plural rotation stand sets may define a rotation plane. A first end of each rotation stand set is fixedly disposed on the rotation base. Each blade is pivotally coupled to a second end of the corresponding rotation stand set through the corresponding deflection structure. Consequently, an angle of attack of the blade in an airflow is correspondingly adjusted. When one of the plural blades is deflected, the corresponding deflection-limiting structure generates a first rotational torque in a first rotating direction or a second rotational torque in a second rotating direction so as to rotate the rotation base.