An M_S6.6 earthquake occurred on August 9, 2017 in Jinghe County, Xinjiang Uygur Autonomous Region, which was followed by a series of aftershocks. Domestic and foreign scientific research institutions have obtained different results for the focal depth of the main shock. In this paper, PTD method is used to determine the focal depth of the earthquake sequence. The result of the main shock is 14km by using the data of Xinjiang Digital Seismic Network and the Xinjiang 2015 velocity model, and the focal depth of aftershocks above M2.5 is between 9~18km. All the seismic phase data is from the catalog database of China Earthquake Networks Center.