There are various types of fracture-cavity deeply buried reservoir with strong heterogeneity in the Ordovician Tazhong area. The model is designed in accordance with real condition in Tazhong area. The complex fracture-cavity reservoir has been found to be equal to a geological model composed of staggered micro-network and cavity which can depict the inner fracture-cavity reservoir structure and parameters variation accurately. It applied the staggered-grid high-order finite difference method of wave equation forward modeling technology to simulate seismic wave field, and used the conventional processing methods and wave equation prestack depth migration to get the migration profiles.