In recent years, environmental issues have received more attention. Good environmental protection measures can ensure the sustainable development of large sites. Based on this, through the analysis of the environmental phytoremediation of Weiyang Palace Site in Han Chang’an City, this paper summarizes the current status and problems of large sites in greening conservation work, and conducts the explorations of the related problems in the large site protection projects combined with the historical style and ecological environment conservation strategies. In this way, when the large sites are conserved effectively, it can promote the economic efficiency and play an important role in the heritage building of Silk Road.