Abstract: Aiming at the technical problems existing in the goaf survey of open-pit metal mine，take⁃ ing a large open-pit iron mine in Anshan-Benxi area as an example，three-dimensional high-density elec⁃ trical detection technique is adopted，multi-azimuths simultaneous data collection is realized by S-type ar⁃ ray pole distribution method，so as to carry out the least square inversion processing with smooth con⁃ straints.And combined with visualization technique，a 3D model of underground space is established to ac⁃ curately detect and study the distribution location and characteristics of underground goaf in open-pit iron mine.The study results show that an air-filled goaf is delineated at a depth of 31 m in a subsidence deforma⁃ tion area of an open-pit iron mine，and the error is less than 3 m compared with the borehole data.It reflects that the 3D high-density electrical detection technology can intuitively display the information such as the buried depth and distribution of underground goaf through the visual 3D model，which can provide a reli⁃ able basis for the safety evaluation and management of goaf.

Key words: open-pit iron mine, goaf, three-dimensional high-density electrical method