Prestack depth migration method and device

The invention provides a prestack depth migration method and device, and relates to the technical field of seismic exploration. The prestack depth migration method comprises the steps that prestack earthquake data of a target working area are obtained; a singular trace in the prestack seismic data is removed to obtain to-be-processed seismic data; a slowness table and an equivalent Q value table are calculated according to the to-be-processed seismic data; according to the slowness table and the equivalent Q value table, a travel time table and a travel time Q ratio table are calculated, wherein the travel time table comprises a shot point travel time table and a detection point travel time table, and the travel time Q ratio table comprises a shot point travel time Q ratio table and a detection point travel time Q ratio table; and deflection hole diameters of all preset imaging points are read, and according to the travel time table, the travel time table and the deflection hole diameters, the deflection ampl