Study of crustal velocity model is very important basic work． It has a long span of 16° from south to north，and 17° from east to west in Xinjiang． Three mountains and double basins， the special topography and complex geological structure have a great influence on the average crustal velocity model of the Xinjiang area． The paper analyzed the 3400 travel time table that has been used in Xinjiang，and obtained the most suitable velocity structure model of the travel time table after fitting． Then a velocity fitting was made by using all data of seismic phase from January 2009 to December 2013，and a simulation analysis of velocity reliability and stability followed． A concept that subarea crustal velocity mode of earthquake concentration area was proposed． Based on all the historical records of earthquake from January 2009 in the area within a radius of 1° with the Yutian MS7. 3 earthquake as the center，crustal velocity model suitable for Yutian area is fitted． The model has been applied in the fine positioning of Yutian MS7. 3 earthquake and the depth of earthquake sequence，and achieved very good results． The process can be used in similar studies．