In the field of UAV-based open-pit mine surveying, most previous studies adopted only one type of UAV for data collection and analysis, without considering the issue of internal and external operation efficiency. Therefor, taking Xiangxiang Dolomite Mine as the engineering background, two types of UAVs, namely Matrice 300 RTK and Mavic 3E, were adopted. External data collection with four different flight heights was carried out in the mining area. In the internal data processing, four image control point layout schemes were selected respectively under each working condition to analyze the measuring point accuracy under different flight heights and different numbers of image control points. Meanwhile, statistical analysis of the internal and external time-consuming under each working condition was conducted, and the surveying operation efficiency of UAV-based open-pit mine was analyzed. The results show that the overall accuracy of the M300 RTK is higher than that of the Mavic 3E under the same working conditions, and as the flight heights increase, the accuracy continuously decreases. Under the working conditions of the same flight height, as the number of image control points increases, the accuracy of the two types of UAVs continues to improve, but the improvement range is not significant. Under the working conditions of the same flight height, the external time-consuming of the two types of UAVs is basically consistent, but the internal time-consuming of the Mavic 3E is only 3.8％ to 8.8％ of that of the M300 RTK. In non-coal open-pit mines with large height difference, the adoption of the Mavic 3E's real-time terrain-following flight combined with the image-control-free mode not only eliminates the field operation step of laying out image control points but also significantly reduces internal time-consuming. While ensuring accuracy, it can greatly improve the surveying operation efficiency of UAVs in mines.