The Qinling Complex is a major tectonic unit in the Northern of the Qinling Orogenic Belt, which is the key to understand the tectonic evolution of the Qinling Orogenic Belt during the early Paleozoic. The migmatites of the Qinling Complex in the Weiziping area, were formed by strong anatexis of meta-sedimentary rocks. In this paper, a combined study of petrology, zircon U-Pb dating and phase equilibrium modeling was carried out on these rocks, in order to better constrain their metamorphic p-T evolution, and tectonic implications. The mesosomes are composed of garnet-bearing hornblende-biotite-plagioclase gneiss, as well as garnet-bearing biotite-hornblende-plagioclase gneiss. The garnet-bearing hornblende-biotite-plagioclase gneiss records only peak mineral assemblage of cummingtonite+garnet+plagioclase+biotite+quartz+ilmenite+melt. However, the garnet-bearing biotite-hornblende-plagioclase gneiss displays three metamorphic mineral assemblages, including biotite+plagioclase+quartz (prograde metamorphic stage, M1), cummingtonite+garnet+plagioclase+biotite+quartz+ilmenite+melt (peak metamorphic stage, M2), and hornblende+biotite+plagioclase+quartz+melt (retrograde metamorphic stage, M3). Phase equilibrium modelling constrained the peak p-T conditions of the garnet-bearing hornblende-biotite-plagioclase gneiss and the garnet-bearing biotite-hornblende-plagioclase gneiss to be 790~810℃/990~1 040 MPa, and 840~862℃/1 000~1 190 MPa, respectively. In addition, the retrograde metamorphic p-T conditions were constrained to be 735~814℃/400~810 MPa, 721~794℃/430~700 MPa, and 740~810℃/470~780 MPa, using p-T pseudosections calculated with local effective composition, for the garnet-bearing biotite-hornblende-plagioclase gneiss. As a result, the meta-sedimentary rocks from the Qinling Complex in the Weiziping area underwent a nearly isothermal decompression p-T path. LA-ICP-MS zircon U-Pb analyses obtain the weighted mean ²⁰⁶Pb/²³⁸U ages of 383.2±7.0 Ma, 400±3.6 Ma, and 406.7±7.8 Ma for metamorphic zircons from garnet-bearing hornblende-biotite-plagioclase gneiss and two leucosome samples, respectively. Integrated with previously published data, the timing of peak metamorphism and strong migmatization of the meta-sedimentary rocks in the Weiziping area is constrained to be ca. 410~390 Ma, whereas the age of ca. 380 Ma may represent the timing of retrograde cooling to the solidus. The nearly isothermal decompression path indicates that the granulite-facies meta-sedimentary rocks in the Weiziping area underwent rapid exhumation, which is interpreted to be resulted from the crustal thickening associated with continental collision and subsequent extension.