The embodiment of the invention relates to the field of exploration, in particular to a method for determining the excavation precision of excavation engineering. According to the method for determining the mining precision of the mining project provided by the embodiment of the invention, the actual three-dimensional point cloud model and the ideal three-dimensional point cloud model of the disposal pit are respectively determined by acquiring the actual physical data and the design data of the disposal pit; the difference of the average distances of the corresponding points between the actual three-dimensional point cloud model and the ideal three-dimensional point cloud model is determined; segmenting the actual three-dimensional point cloud model to obtain a plurality of actual sub-three-dimensional point cloud models, so as to determine the maximum horizontal distance between internal points of the actual sub-three-dimensional point cloud models and the offset of each actual sub-three-dimensional point cloud model relative to the ideal three-dimensional point cloud model, and calculating the actual three-dimensional point cloud model according to the difference of the average distances, the maximum horizontal distance and the offset. And determining and comprehensively evaluating the excavation precision of the disposal pit so as to guide later buffer material building block installation and research and development of disposal pit excavation equipment.