In order to acquire the original wavefront information in radial shearing interferometry, wavefront reconstruction is necessary, the iterative algorism for wavefront reconstruction was deduced in this paper, based on which an numerical simulation using Matlab with different iteration number and shearing ratio was conducted. The simulation comes to the following conclusion: Properly selection of the shearing ratio can simplify the computational complexity. Compared with the small distortion wavefront reconstruction, more but appropriate iteration number in large distortion wavefront reconstruction is needed. Preferred shearing ratios for different measured wavefront PV values are summarized as follows: a. if WPV>10λ, beta>0.7; b. if 6λ