Currently, there are many controversies about the timing and subduction mode of the tectonic evolution of the Bangong-Nujiang Suture Zone but there is a large area of early Cretaceous magmatic rocks in the north of Lhasa. Through the study of its genesis and formation background, it can effectively reveal the magmatism and dynamic process of the early Cretaceous Lhasa terrane. A comprehensive study has been carried out on dacite and rhyolite in Daguo area of Shenzha County. The results show that the zircon LA-ICP-MS U-Pb ages of dacite and rhyolite are 115Ma and 109Ma, respectively, indicating that it was formed in the early Cretaceous. The dacite and rhyolite is characterized by high contents of SiO2（61.97%~72.32%）, K2O+Na2O （6.51%-8.72%）, with low contents of A12O3 （12.62%~14.16%）, and a Rittmann index （σ43） of 1.84~2.59, aluminum saturation index（A/CNK）0.85-1.21; There are significant negative Eu anomaly（δEu=0.45~0.59）and a "V-shaped" rare earth element curve gently inclined to the right. In addition, the rocks has high whole-rock Zr saturation temperatures （811.70~900.82℃）, and has high values of FeOT/MgO（7.39~29.95）, HFSE（485.82~678.69）, 1000*Ga/Al（2.36~3.12）、Y/Nb （2.67~4.06）、Rb/Nb （6.94~13.92）, These characteristics indicate that it has the characteristics of A2 type granite. The Hf isotoppic compositions in the dacite and rhyolite-1.73 to 1.88 and -2.64 to 1.6,The values of mg # are lower (4.79-20.14), and have high (Na2O+K2O) / Al2O3 (0.46~0.66) and TiO2/MgO (1.07~2.98), which are similar to the melt values produced by high temperature melting experiments of quartz diorite or granodiorite, and are presumed to be the product of partial melting of the diorite or granodiorite new crust. It is speculate that the studied rocks were formed during the subduction-ablation phase of the southward-subducting Banguang-Nujiang Ocean lithosphere, where mantle-sourced material upwelled as a source of heat, causing partial melting of the crust, and undergoing the segregation of plagioclase feldspars, potash feldspars, and ilmenites into crystalline formations.