Abstract: In order to solve unstability problem of signaling centralized and locking system in mine which uses sensors to distinguish and locate locomotives, the paper introduced a method of locomotive location of coal mine underground by use of speed-measured technology by video. The method uses distance-measured technology of binocular stereo vision to get running distance of locomotive, obtains real-time running speed of locomotive according to interval of two sequential images, and converts the running speed of locomotive to moving speed of a corresponding simulated ball, thus dispatchers can monitor running status of locomotive through observing moving status of the simulated ball, namely the method can realize function of locomotive location.