An Early-Middle Silurian granodiorite rock was found for the first time in Kuerliang Group during the process of the 1∶50 000 geological survey in Kuerliang area, northern West Kunlun Mountains. Through the LA-ICP-MS zircon U-Pb geochronological study, a weighted mean ²⁰⁶Pb/²³⁸U age of 429.6±1.4 Ma(MSWD=0.69) for the zircons in granodiorite was obtained. Geochemical characteristics show that the granodiorite is typical adakite with high SiO₂(68.85%~72.49%), Al₂O₃(14.08%~15.36%), Sr(480×10^-6~ 812×10^-6), Sr/Y(53.2~111.0), and low Y(7.31×10^-6~10.30×10^-6), Yb(0.34×10^-6~0.48×10^-6). In addition, it exhibits significant fractionation between LREE and HRE and is depleted in HREE with slight Eu anomaly(0.86 < δEu < 1.03, 0.98 on average). The rock has a relatively high proportion of K₂O(2.92%~3.48%) and low proportions of MgO(0.69%~0.84%), Mg^#(26.4~32.6), Cr(15.1~28.2), and Ni(3.54~5.39), with Na₂O/K₂O ratios being 1.03~1.46(1.21 on average). These characteristics suggest that the granodiorite was a product of partial melting of a thickened lower crust, and a crustal thickening occurred in the West Kunlun Mountains in Early-Middle Silurian when the crustal thickness was greater than 50 km. Together with regional geological data, the authors hold that the Proto-Tethys Ocean basin, taking Kuda-Qimanyute ophiolite mélange as a symbol, had been closed before Early-Middle Silurian, and then entered the collisional orogenic period. This research provides a reliable petrological evidence and precise chronological data for the collisional orogenic event after the closing of Proto-Tethys Ocean.