With the rapid pace of urbanization, construction land is growing sparse, so it has become more common for landfills to be used as engineering sites. As such, to explore the physical and mechanical properties of various soil types in landfills and the necessary treatment measures to be taken, we studied the foundation treatment and construction of a landfill site in the Xi'an North EMU depot. Based on indoor tests and in-situ field measurements of the landfill soil, we quantitatively analyzed the engineering properties of miscellaneous fill ground. In this paper, we propose a reasonable foundation treatment plan. The related engineering operations verified that all the foundation parameters met the design requirements and achieved the desired effect after excavation, replacement, and dynamic consolidation of the foundation. Moreover, we also applied an innovative method of mixing quicklime into the solid waste, which prevents secondary pollution. Our research results can be used for reference in other landfill foundation treatment projects under similar conditions.