Abstract: he volume calculation of open-pit mine is one of the key technologies in open-pit mining，however，the amount of engineering is difficult to be accurately calculated by traditional methods because of the complicated geometry of open pit mine influenced by natural conditions and mining process.A method for calculating the volume of open-pit mine based on tilt photography of unmanned aerial vehicle (UAV) is proposed，which adopts the unmanned aerial vehicle equipped with digital oblique cameras for image sequence acquisition in open-pit area.Through feature extraction，aerial triangulation，multi-image dense matching，3D point cloud are generated.Based on this，through irregular triangular gridding and texture mapping，3D model of open-pit slope are reconstructed automatically，and finally grid method is used for volume calculation of open-pit mine.An open-pit aluminum mine in Mianchi，Sanmenxia，is selected for experiment，and the results show that the engineering volume of open-pit can be rapidly obtained by using this method，with the characteristics of high efficiency and low cost.It provides a new method for rapid calculation of open-pit mine volume under complicated conditions.

Key words: UAV oblique photography, Open-pit mine, Dense point cloud, Grid method, Volume calculation