Point cloud data obtained by unmanned aerial vehicle (UAV) photogrammetry were used as the basis for creating a 3D model. In this study, we calculated earthwork volume using a 3D model based on such point cloud data at a construction site. An expressway construction site was selected as the study area, and UAV photogrammetry was performed three times, and for comparison purposes, traditional surveying was also conducted the same number of times. Comparison of the earthwork volume calculated by the two methods showed that the volume calculated by UAV photogrammetry was larger in the range of 2.36–2.51% than that obtained by the traditional surveying method (TSM). Therefore, it was found that the method of calculating the earthwork volume at the construction site could be changed to UAV photogrammetry. In addition, comparison of the work efficiency of the two methods showed that UAV photogrammetry in the first work in the study area consumed twice the work time and 1.4 times the work cost over TSM; however, from the second work onward in the study area, the work time and work cost were reduced by approximately half. Therefore, it was found that work efficiency improved as the number of jobs increased.