The invention relates to an VSP data wave field separation method. The VSP data wave field separation method comprises steps of performing wave field pickup on VSP data to be processed to obtain information of multiple groups of wave fields, recording position of an event of each group of wave fields, for each in-phase axis and targeting each point on the event, delimiting a time window for the point according to the position of the point, and for each event and targeting each point on the event, performing one-dimensional median filtering processing on the point according to the time window delimited for the point. The VSP data wave field separation method eliminates processes of flattening and pull-back in the prior art, can process multiple groups of wave filed information at the same time and improves efficiency of wave field separation.