Using null lens such as computer-generated hologram (CGH) is almost the routine for testing asphere at present. The using of on-axis CGH has many advantages, but the central area of the asphere can not be tested due to the ghost. In this paper, a new program is proposed, where the influence of ghost is eliminated by using off-axis CGH and modified Twyman-Green interference setup. In this program, the off-axis CGH is placed on the imaging arm, compensating the testing wavefront secondly and separating the varied diffraction orders in the direction of vertical axis. With the tilt axis and filter, 0th order of the reference wavefront and -1st order of the testing wavefront are adopted to get interferograms which are used to carry out the aspherical testing. In our proposed program, the asphericity is compensated with the combination of standard spherical lenses and off-axis CGH. For comparison, the same asphere is tested by on-axis CGH with Zygo interferometer. The experimental results confirm that the ghost image is eliminated successfully, the results of the two tests keep well agreement, and this program can be used to test large aperture asphere on high accuracy.