Abstract: The formation and evolution of the Zanda basin as an intermontane downfaulted basin in the Himalaya tectonic belt are closely related to the basin-controlling tectonic movement on both sides of the basin. The finite element numerical simulation of the tectonic stress field of basin-controlling faults will be helpful to further understanding the basin-controlling tectonic characteristics in the area. Therefore, based on a detailed survey of the tectonics, combined with the deep geological and geophysical data of the area, the tectonic stress field of the basin-controlling faults in the Zanda basin was simulated. The results show that the formation and evolution of the Zanda basin were obviously controlled by the boundary faults on both sides of the basin. The formation of the Zanda basin is the result of the differential uplift of different blocks under the N-S compressional stress. The basin-controlling faults on the south are north-dipping normal faults and those on the north are south-dipping thrust faults, both of which combine to generate a process of seesaw-type tectonic downfaulted basin movement (the south descended and the north ascended). It is a way of adjusting the tectonic stress field of the Himalayan block in the whole synchronous convergent compressional environment.