Abstract: To address the problem that conventional borehole radar has difficulties in performing directional detection of surrounding targets due to the effects of radar wave propagation characteristics and complex geological conditions in mines, research on directional borehole radar antenna technology and directional detection methods has been conducted. First, through the simulation design of the radiation surface and shielding structure, the antenna structure was optimized to improve its focusing radiation ability and effectively reduce signal interference in the mine environment. Next, impedance matching was achieved through resistance loading simulation analysis to improve the antenna's radiation efficiency and optimize its structural parameters. Finally, the radiation surface aperture angle was selected to be 60°, and the shielding shell height was set to 40 mm. A borehole radar directional recognition model was then constructed, and a detection method based on the amplitude spectrum ratio method was proposed to determine the anomalous azimuth angle within the mine borehole. Experimental results in the mine show that this directional borehole radar can accurately detect and identify the radial detection depth, distance from the borehole opening, and relative azimuth of coal-rock interfaces and small fault structures. The detection depth error is less than 0.01 m, and the deviation between the detected and actual target azimuth is less than 1°.