The Baoshuping Formation of the Erlangping Group is an important Early Paleozoic sedimentary record in the North Qinling Mountains, but it has not been studied enough. This study aims to further determine its depositional age and tectonic environment through petrological, geochemical, and zircon U- Pb dating investigations of volcanic interbeds and granite veins within the Baoshuping Formation. The research results indicate that the lithology of the volcanic interbeds of the Baoshuping Formation in the Xiaguan Town, Neixiang County, western Henan Province, is biotite actinolite sodium schists, often interbedded with biotite quartz schists. The protolith of the rocks is andesitic tuff, characterized by relatively low SiO2 (52.56%~62.04%), relatively high Al2O3 (10.70%~18.55%), low MgO (4.06%~6.21%) and FeOT/MgO (1.23~1.81).It is enriched in light rare earth elements (LREEs) and large ion lithophile elements (LILEs, Rb, Th, U, K), and relatively depleted in high field strength elements(HFSEs, Nb, Ta, P, Ti), exhibiting characteristics of magnesian andesite rocks. Based on geochemical characteristics and previous studies, it is inferred that the Baoshuping Formation may have formed in an active continental margin back- arc basin. The crystallization age of the protolith of biotite actinolite sodium schists obtained by U- Pb dating of zircon is 446.0±1.7 Ma, and the crystallization age of the intrusive granite porphyry is 430.0±3.0 Ma, accurately dating the formation age of the Baoshuping Formation as Late Ordovician to Early Silurian for the first time. Integrated regional research results suggest that the Xiaozhai Formation and Baoshuping Formation conform to the division scheme of the generalized Erlangping Group in terms of stratigraphic sequence and stratigraphic age. However, the Damiao Formation, Huoshenmiao Formation, and the composite of the Xiaozhai Formation and the Baoshuping Formation exhibit near- simultaneity in formation age and a nearly parallel spatial relationship, indicating that they are likely products of different depositional environments with roughly equivalent ages. In terms of tectonic attributes, it is believed that the Erlangping Group formed as a volcanic island arc due to the northward subduction of the Shangzhou—Danfeng Ocean before approximately 470 Ma, transformed into a back- arc basin between 470 Ma and 436 Ma, and completed the subduction closure process before approximately 430 Ma.