Abstract: The northeastern margin of the Qinghai-Xizang Plateau, as the leading edge of the plateau's expansion into the interior of the Asian continent, holds significant importance for understanding the lateral expansion mechanism of the plateau and the deep dynamic background. With the improvement in computational capabilities and the development of advanced numerical methods, adjoint tomography based on seismic wave equation has been widely applied to crust and mantle structure studies on regional to global scales, deepening our understanding of the Earth’s internal structure and dynamic processes. This paper reviews the research progress of adjoint tomography in the northeastern margin of the Qinghai-Xizang Plateau, focusing on the spatial distribution of mid-to-lower crustal flow, interactions between different tectonic blocks, and the mechanisms of large earthquake generation in the region. The research shows that there is widespread mid-to-lower crustal flow within the Songpan-Ganzi Terrane, which extends northward across the Kunlun Fault and terminates in the central Qinling-Qilian Terrane. In contrast, the mid-to-lower crust beneath the Qinling Orogenic Belt is characterized by high velocity, suggesting that weak crustal material from the Qinghai-Xizang Plateau has not flowed into this area. Additionally, the lithospheric basement beneath the Sichuan Basin extends westward into the interior of the plateau and reaches near the Longriba Fault Zone. This indicates that the Longriba Fault Zone serves as an important tectonic boundary between the Qinghai-Xizang Plateau and the Yangtze Block, potentially representing the westernmost edge of the Yangtze Block. Furthermore, the study reveals that large earthquakes in this region frequently occur in areas with high gradients in seismic velocity and radial anisotropy or in transitional zones between high and low gradients. This finding enhances our understanding of the mechanisms of large earthquake generation in the northeastern margin of the Qinghai-Xizang Plateau. The complex tectonic interactions and resulting deformation processes play a crucial role in shaping the seismotectonic environment of this area.