Rural residential building is one of the main building types, its building energy consumption accounted for 22% of the total in China. As the lack of building energy conservation awareness, most rural dwellings have a common phenomenon contains poor indoor thermal environments and energy wasted. To investigate a feasible measure of rural residential buildings in Guanzhong plain, a study was conducted to find the optimal measures for achieving energy efficiency. In this study, the field measurements of a typical rural residential building selected in Xi’an during the coldest month shows low temperature and black ball temperature indoor. Numerical building simulation illustrated this building has large energy-saving potential. An economic analysis of energy-saving measures for the optimal scheme combined with the investment payback period method found that the payback period was the shortest when the wall and roof are optimized for energy saving.