The geodynamic origin of the abrupt change in the tectonic setting of the Tarim basin in the Early Paleozoic has long been the focus of controversy. In this paper, detrital zircon U- Pb geochronology was performed on sandstone samples from the Cambrian- Silurian section in the Wushi area, northwest margin of Tarim basin, to determine the provenance system and describe the sedimentary tectonic evolution in the area. The results show that the detrial zircon samples record five tectonic thermal events occuring in ~ 500 Ma, ~ 800 Ma, ~ 1000 Ma, ~ 1800 Ma, and ~ 2500 Ma. Compared with the potential sources, the provenance of the Upper Cambrian probably resulted from regional uplifting in Keping or nearby areas, as well as weathered errosive ancient rocks within the basin. By the Early Silurian, the Kunlun orogenic belt had become one of the provenances of the study area, and also indicates that the Kunlun Ocean has been subducted and closed and even uplifted to form high mountains in the Early Silurian. According to the previous studies, it can be concluded that the reason for the abrupt change of tectonic background and the disappearance of the platform in the Tarim basin in the Late Ordovician may derive from the subduction and closure of the ocean basin in the south of the basin. Moreover, some further work needs to be carried out to decide whether there was the involvement of oceanic basin in the north. However, although there is some influence from the oceanic basin, its impact and scope should be far less than that in the south.