Abstract: In order to verify the occurrence status of concealed rock mass in Yinjiahui area of Anhui Province, and delineate the range of intrusive intermediate acid-acid rock mass and advantageous ore-bearing location, the author has polarized and continued the magnetic anomalies, and processed the anomaly separation of magnetic source from different depth fields and vertical derivative. The author has also extracted some useful information about residual magnetic anomalies and the first vertical derivative of magnetic anomalies. Combined with the magnetic anomalies characteristics based on geology data, the results show that the NE residual magnetic anomaly zone formed from the intruded vein along the fault and the NE fault is the main rock-control and ore-control structure. The author also concluded that magnetic geologicalbody, resulting in local residual magnetic anomalies, is concealed and semi-concealed intermediate acid-acid rock mass. This research would provide some reference for the division of geological survey and prospective metallogenic zones, and the outlining of prospecting targets in Anqing-Xuyi geological and mineral resources survey in middle and lower Yangtze metallogenic belt.