The idea and method for designing aspherical Intraocular Lens (IOL) were proposed. First, the wavefrontaberration was calculated according to the corneal topography, and then, based on the wavefront aberration expressed asZernike polynomial Z40, the aspherical IOL was designed. The imaging quality of two practicable eyes implanted with aspherical and spherical IOLs of power 9.5D and 20.5D was analyzed. The results show the Modulation Transfer Function (MTF), contrast sensitivity and defocusing MTF of eye implanted with aspherical IOL are better than those with spherical IOL. The aspherical IOL displays more excellent optical performance than traditional spherical IOL, and the method is feasible to design aspherical IOL. The results provide theoretical bases for the clinical application of aspherical IOL.