The Subei Fault is located in the western part of the Yema River-Daxue Mountain fault, which is located in the northeast of the Tibetan Plateau. This fracture is about 17 km long, trends northwest 40°, and crosses the Altyn Tagh Fault in the Subei area. The conventional view is that the power of the Altyn Tagh Fault with a high slip rate (about 10 mm/a) was absorbed by the Tanghe Nan Shan fault, the Yema River-Daxue Mountain fault, the Changma fault, and so on. Some of this power was also tranversed to form a thrust fault, after which the slip rate of the Altyn Tagh Fault decreased to 1~2 mm/a. There has been little formal research and no systematic study made of the late Quaternary activity along the Subei Fault. Using high-resolution satellite imagery and systematically studying the Subei Fault area, we generated complete geology maps of the Subei area at a scale of 1∶25,000 and some maps at a scale of 1∶5,000. In addition, we completed other tasks, including a trench study, ¹⁴C sample dating, and measurements made by small unmanned aerial vehicles (sUAVs). Our conclusions are as follows: The Subei fault is a Holocene thrust fault that has exhibited multiple-staged activity since the late Quaternary, based on the structure transform mode put forward by Xu Xiwei in 2003. Moreover, our study shows the sUAV to have broad application prospects. We can rebuild a digital elevation mode based on hundreds of pictures collected by sUAVs with a very high precision. Using this technology, we can also build digital orthoimages any places we wish. Using digital elevation models (DEMs), we chose typical landforms and extracted their profiles to show the altitude of the scarps. We compared the altitudes measured by the DEM profile with measurements by the laser range finder, and found the measurement results to be basically the same. Combining several fault profiles along the Subei Fault and that of a trench excavated in Xishuigou, we determined that the Subei Fault is mainly a thrust fault, with linear and continuous scarps along the fault.