The virtual grating Moiré fringe is a method to acquire the test wavefront using single interferogram. The Gaussian function is used to filter Moiré interferogram in the spatial domain. The Moiré interferogram is blurred by Gaussian filter in the spatial domain, thus the high frequency component is filtered out, leaving the low frequency component which contains the test phase information. The relationship between the window of Gaussian filter and the carrier frequency of the interferogram is given. The amount of calculation of the method is low and it is easy to select the filter window. The wavefront of a plane is measured using Zygo phase shifting interferometer, whose result (dPV=0.080λ, xRMS=0.020λ, λ=632.8 nm) coincides with the one obtained by the virtual grating Moiré fringe method (dPV=0.079λ，xRMS=0.017λ).