Abstract: The Guangde basalt mining area is largely covered by the Quaternary system，and it is dif⁃ ficult to find hidden basalt ore bodies by traditional geological mapping. By analyzing the physical proper⁃ ties of basalt，the high magnetic susceptibility of basalt is used to delineate the basalt target area efficient⁃ ly. A total of 14 magnetic anomalies were found in this high-precision magnetic survey. Basalt deposits were found in 7 of the magnetic anomalies drilled through trenching verification. The magnetic anomaly pro⁃ duced by basalt has a large peak value and a steep gradient，and the magnetic profile curve jumps in a jag⁃ ged shape and changes drastically. In the case of few surface basalt outcrops，high-precision magnetic sur⁃ veying can be used as an effective means to find basalt ores.

Key words: basalt mine, high-precision magnetic method, magnetic susceptibility