Since practical data information often contains small-amplitude wind speed and singularity point because of lots of disturbance such as earth-surface clutter, we put forward a method of pretreatment for quality control to data information before the velocity azimuth display (VAD) data inversion, which eliminates small-amplitude data and singularity point, then we proceed omnidirectional sampling and non-omnidirectional sampling inversion respectively. The precision of inversion is improved a lot, and the result of the simulation is consonant with reality. We simulate two kinds of linear wind field, that is, the linear wind field with the zero, first order harmonics and the zero, first, second order harmonics. We research into the omnidirectional sampling and non-omnidirectional sampling VAD methods by using the two kinds of wind field′s comparison. The result of this simulation indicates that the omnidirectional sampling VAD method has high performance in both two kinds of linear wind field′s inversion results, while the non-omnidirectional sampling VAD method has a very small effective sampling range in the linear wind fields without the second order harmonic, meanwhile, this method is affected by the second order harmonic partly.