The Qinling Orogen is located between North China Block (NCB) and South China Block (SCB) in central China,being proposed a composite collision orogen composed by the North Qinling Belt (NQB) and South Qinling Belt (SQB) [1].The previous studies proposed the NQB as an early Paleozoic active margin of NCB [1～5] and underwent three episodes of arc-continent collision during the Paleozoic continental convergence between the NCB and SCB [6].However,new research results revealed that Shangdan ocean was closed at 520 Ma along the Shangdan Suture Belt (SSB) during Early Paleozoic [7],and the continent-subduction dragged by the northwards subduction of Shangdan ocean started around 500Ma and then experienced two stages of exhumation ca.