The rural homestead is a major part of the rural land system, which is an important carrier of various rural issues such as rural decline, rural hollowing and others. Great changes have occurred in China's rural areas, while the rural homestead has also undergone transformation. Based on summarizing the multi-functional classification of homesteads from previous research, this study divided and defined the population bearing function, assets, and residential function of homesteads from the perspective of functional improvement according to the results of a survey questionnaire. Using Poyang County as the case study, this paper analyzed the functional transformation of rural homesteads through the model of coordinated transformation degree. The results demonstrated the following trends. (1) From 2000 to 2017, the transformation degrees of rural homestead functions in Poyang County have obviously improved overall. (2) The high value areas of the transformation degrees were mainly distributed in the northern hilly region and around Poyang Lake, while most of the low value areas were distributed in the plain areas near the county town. (3) In the regions with better location conditions and resource endowments, the basic conditions and trend of non-agriculturalization of the population, capital and other factors are more significant. According to the differentiation of rural homestead transformations which occurred in different regions, the government could put forward targeted development suggestions for the future.