According to the China Earthquake Network,a magnitude 7.4 earthquake struck Madoi County in the Guoluo Tibetan Autonomous Prefecture of Qinghai Province on May 22, 2021. The epicenter was located within the Bayan Har block,situated in the central region of the Tibetan Plateau. Unlike typical magnitude 7 earthquakes,which generally occur along block boundary zones,this was a significant intra-block event,prompting widespread interest in whether the earthquake indicates block disintegration or heightened stress accumulation within the block. In response to this,our study utilized GNSS and Sentinel-1 InSAR data to calculate the isoseismic deformation field of the Madoi earthquake. This data served as a constraint in inverting the subsurface dislocation distribution along the seismogenic fault using an elastic semi-infinite dislocation model. The InSAR coseismic deformation fields revealed substantial surface deformation,with maximum line-of-sight(LOS) displacements of 1.1 meters on the ascending track and 0.9m on the descending track. Our findings indicate that the earthquake produced a significant surface rupture stretching approximately 160km,extending from the Changma River in the east to Lake Ereung in the west. The coseismic slip model results suggest that the seismic fault system comprises a main fault and a secondary fault. The main fault dips northward at an angle of 85° with an average slip angle of -11.25°,while the secondary fault dips southward at an angle of 68° with an average slip angle of -11.39°. The seismic rupture was primarily concentrated between 0 and 17km depth,with a maximum slip of approximately 4.34 meters. The moment magnitude derived from the inversion was M_W7.4. The rupture area contained four asperities and represented an asymmetric bilateral rupture event. Based on aftershock relocations,field investigations,and tectonic background analysis,we determined that the primary seismic rupture occurred along the Kunlunshankou-Jiangcuo fault. Furthermore,the earthquake significantly increased extrusive stress accumulation in the northeastern Bayan Har block,particularly along the Machin section of the East Kunlun Fault. These findings highlight the need for further in-depth study and monitoring of stress accumulation in the region.