Abstract:OBC sensors are often drifted in TZ or offshore seismic exploration.Therefore getting the real positions of the sensors is needed during data processing.Nowadays the sensors secondary positioning has become more and more important for OBC data acquisition quality.We analyze in this paper the advantage and disadvantage of the acoustic secondary positioning method and the first breaking secondary positioning method.Based on these traditional secondary positioning methods,we present a new first breaking secondary positioning method named scanning-fitting method.This method determines secondary positioning coordinates of sensors by scanning grids,fitting curved surface and solving the extreme value of the curved surface.The application to real data shows that this new method has the advantages of high efficiency and high accuracy.