Abstract: In view of problems of low ranging accuracy, small measuring range and high cost of existing obstacle detection and ranging method of mine locomotive, an obstacle detection and ranging method of mine locomotive based on monocular vision was proposed. Firstly, the method preprocesses image captured by CCD camera, then extracts feature according to characteristics of the obstacle, so as to get accurate obstacle region. Finally, it uses monocular vision ranging method based on camera interior parameters and geometrical relationship to get distance between locomotive and the preceding obstacle. The test results show that the method can detect the obstacle ahead of locomotive effectively and ranging accuracy is within effective error range.