Re-understanding of the gravity anomaly of the Linxiang polymetallic ore-forming area in northeastern Hunan Province and its geodynamic mechanism was obtained mainly by means of vertical second derivative. The authors inferred the distribution of the structural framework and the concealed rock bodies of the study area, summarized the relationship between the gravity anomalies, the concealed rock bodies and the fracture structures in the known ore spots (ore bodies). It is concluded that there still exists the potential of finding large polymetallic deposits. The results obtained by the authors provide important geophysical evidence for deep ore prognosis.