LCTV's phase modulation characteristics has been analyzed in this paper. Then a phase plate that can make a plane wave become a step-jump wavefront is inserted into a specific plane of incident light path of a cyclic radial shearing interferometer. And a gray distribution that can produce a conjugated wavefront of the step-jump wavefront was input the LCTV. The experimental result shows that the step-jump wavefront has been compensated ideally.