Ecological construction experience of traditional dwellings has been widely recognized. The construction technology of traditional houses on thermal environment has unique characteristics in Bayu region because of its special topography and climate. A rural earth building in Jiangjin district, Chongqing was used as the research object. Field measurement was carried out to record the residential indoor thermal environment throughout the year. and the data was adopted in numerical simulation analysis to evaluate indoor thermal conditions The results showed that the earth wall was more effective to for improve thermal environment in summer and indoor thermal environment in winter was far worse than that in summer. The attic space in earth building had significantly positive affect on indoor thermal environment because of its heat preservation in winter and heat insulation in summer.