On April 5, 2017, SefidSang earthquake with moment magnitude of 6.0 occurred in Khorasan Razavi province in Iran. Its epicenter was about 30 km of the city of SangSedid and 80 km of the city of Mashad. In this research, to obtain the least possible error in locating the earthquake double-difference method (using HypoDD software) is used to reduce the errors associated with the crust model. The HypoDD program has been used for relocating of the earthquake. In this method, the error caused by the crust model is reduced to improve the location of events using the double-difference approach. The mentioned method has a significant impact on improving the depth distribution of earthquakes in this area. Due to the distribution of Aftershocks, the causetive fault has a northwest-southeast trend (parallel to the Kashafrud fault and at the end of the fault).