The concept of equivalent offset migration (EOM) method is introduced to vertical seismic profile (VSP) in the paper. The definition of the VSP equivalent offset migration and data processing method based on VSP equivalent offset migration method are also introduced. The EOM method, which has particular advantages in velocity analysis and imaging, provides ideas for VSP scattered wave imaging and velocity analysis. The results of theoretic test and analysis of real data show that the VSP equivalent offset migration method is effective and feasible, and has the prospect of study and application.