This paper studied the deformation field and seismogenic structure of the Menyuan M_S6.9 earthquake in Qinghai Province on January 8, 2022, by using the ascending and descending Sentinel-1A data and the differential interferometric synthetic radar (D-InSAR) technique. The source parameters were then inverted to determine the fault geometry parameters and the non-uniform fault slip distribution with a dislocation model in an elastic half-space. The results showed that the coseismic deformation field of Menyuan earthquake is distributed along the NWW-SEE direction. The maximum surface deformation of the ascending and descending images on the southern edge of the fault zone are 61 cm and 62 cm, respectively; the maximum surface deformation of the ascending and descending images on the northern edge of the fault zone are 43 cm and 56 cm, respectively. The fault scale model of InSAR coseismic deformation field is 30 km long and 18 km wide, with the maximum slip of 3.5 m. Combined with the movement characteristics and geometric characteristics of Lenglongling fault, it is determined to be the seismogenic fault of Menyuan M_S6.9 earthquake.