Abstract: The Qianchang East copper iron deposit in Anhui Province is a deep ore block of the Qianchang copper iron deposit. In order to understand the underground electrical structure features of Qianchang East ore block, 3D controllable source audio frequency magnetotelluric exploration was carried out in this ore block. 3D data was collected in the form of multi-panel combination, and the data inversion was conducted with Occam inversion method. The inversion results were mapped in 3D form, which shows the underground electrical structure of the area from multiple angles. The results indicate that the Quaternary thickness of Qianchang East ore block ranges between 100 m and 200 m, and gradually thickens northeastward. The marble mainly occurs in the southwest corner of the mining area. The Sanpu complex pluton becomes deep to NE and shallow to SW in shape. The 3D controllable source audio frequency magnetotelluric exploration clearly reveals the deep electrical structure features of the ore block and provides support for the deep prospecting in the area.