Abstract: Drilling tool drop is a common borehole accident in directional drilling in underground coal mine. In view of the problems existing in current treatment measures, such as non-visibility of the process, blindness of the measures and the possibility of secondary borehole accident, a visual treatment technology for borehole accident in underground coal mine is put forward. Based on the analysis of the accident borehole, the technical principle and supporting device of the visual treatment technology for borehole accident is introduced, the reasonable accident handling drilling assembly is selected, and the visual treatment process is established. The application test is carried out in the accident borehole of the drilling tool drop in Qinglong Coal Mine, and the drop fish is successfully fished out of the accident borehole. The application test shows that the artificial push depth of the mine borehole imager reaches 143 m, and the image and video information of the borehole fish is obtained successfully, which can be used for auxiliary judgment about the condition inside borehole. The technology can meet the requirements of visual treatment of borehole accident.