We propose an orbital angular momentum (OAM) generator consisting of two conjugated electro-optic spiral phase plates with two longitudinal electrodes, which enables us to realize the electrically tunable generation of integer or noninteger optical vortices according to the input photon's polarization. We demonstrate that such an OAM generator allows the electro-optic management of the multidimensional OAM vector states, and it would have potential applications in quantum information processing system.