Method for separating variable offset vertical seismic profile (VSP) wave fields

The invention provides a method for separating variable offset vertical seismic profile (VSP) wave fields. The method comprises the following steps of: inputting the collected original seismic wave field data of the variable offset VSP in a computer; performing t2 stretching treatment on the original seismic wave field data to form t2 stretching processing data; performing discrete positive parabolic radon transformation on the t2 stretching processing data to form tau-q domain up-going wave separation data and tau-q domain down-going wave separation data; performing discrete reverse parabolic radon transformation on the tau-q domain up-going wave separation data and the tau-q domain down-going wave separation data to form x-t2 domain data; and performing reverse t2 stretching treatment on the x-t2 domain data to separate the up-going wave and down-going wave of the variable offset VSP.