Abstract: Due to the influence by the mining process and the natural conditions，the geometric shape of open-pit slope is complex and it is difficult to describe completely by the traditional measurement method.The technology of three-dimensional automatic reconstruction based on imagine is introduced to the computer vision field，and then，a perspective camera model for the distant scenes imagine is built.With the use of robust self-calibration algorithm，a three-dimensional model of slope can be automatically built through the non-metric digital open-pit mine slope photos.According to the acquisition and processing of the above distant-scene image，a field test on a slope which belongs to Anqian Mining Company was carried out.A three-dimensional slope model was acquired under different numbers of the photos，which means that the three-dimensional modeling technique of open pit slope is feasible.Moreover，higher precision model could be acquired under the condition of less original pictures.So it can effectively reduce the work of the data collection and the cost of three-dimensional modeling and improve the efficiency of surveying and mapping open-pit mine.It has important significance in the field of three-dimensional terrain and landslide hazard analysis in open pit mine.

Key words: Open-pit mine, Slope, Photography measurement, Three-dimensional modeling