The invention belongs to the technical field of seismic
data acquisition and
processing, and particularly relates to a method and a device for acquiring a seismic
diffraction body. The method comprises the following specific steps: preprocessing collected seismic data to obtain seismic shot gather data which can be directly used for migration; eliminating
residual noise by using a multi-channel
singular spectrum analysis technology to obtain optimized pre-stack gather data; a complete diffracted wave is obtained through forward and
reverse transformation of a virtual seismic source and through offset-reflected wave removal-deoffset; and finally, accurately separating weak signals of the diffracted
waves under the condition of intersection and tangency of
seismic wave fields by researching characteristics that the polarity and the amplitude of the diffracted
waves change along with an emergence angle and an
azimuth angle, thereby realizing high-resolution
diffraction body imaging of the fractured-vuggy reservoir, effectively improving the imaging precision of the
karst fractured-vuggy reservoir, and achieving the purpose of fine detection of the fractured-vuggy reservoir. The method is of positive significance to clarify the seismic response of the fracture-vug type reservoir, implement fracture-vug distribution characteristics and guide effective identification of the
karst type reservoir and optimization of a favorable target area.