With special genetic mechanisms, adakitic rock is one of the important rock probes for exploring the deep magmatic dynamic process and regional tectonic evolution. In this paper, zircon U-Pb age, major and trace elements and zircon in-situ Hf isotopes of the Shiwali granite from the eastern part of the North Qilian orogenic belt were systematically analyzed to explore its petrogenesis and geodynamics significance. LA-ICP-MS zircon U-Pb dating yields an emplacement age of 452 ±4 Ma for the Shiwali granite, indicating a product of Late Ordovician magmatic activity. Bulk-rock analyses show that these rocks contain high SiO₂ (68.60%~71.42%), Al₂O₃ (14.95%~15.75%) and Na₂O (5.06%~5.79%) contents, with low K₂O (2.23%~3.10%) and MgO (0.91%~1.73%) contents, and resultant high Mg^# value (55~59), belonging to the weak peraluminous and calc-alkaline series of rocks. These rocks have high concentrations of Ba (1 025×10^-6~1 250×10^-6), Sr (324×10^-6~577×10^-6) and low Y (6.99×10^-6~7.69×10^-6), Yb (0.65×10^-6~0.71×10^-6) contents, with high Sr/Y (45~79) and (La/Yb)_N (17~31) values, and no significant negative Eu anomalies. The εHf(t) values of zircons are relatively high, with a range of +0.5 to +15.5. The geochemical and zircon Hf isotopic compositions of the Shiwali granites are similar to that of high-Mg adakites, which may be the product of partial melting of the basic lower crust of the island arc at a depth of 30~40 km, and there may be Early Paleozoic juvenile crust in the source area. Combined with the research results of ophiolites, high-pressure metamorphic rocks and arc magmatic rocks in the study area, we suggest that the Shiwali high-Mg adakitic granites might be generated during the southward subduction of the oceanic crust in the Laohushan back-arc basin in the Late Ordovician, which affected by the northward subduction of the North Qilian Proto-Tethys ocean.