Abstract: Under the background of rapid urbanization, promoting high-quality land use transformation is an important way to achieve sustainable and coordinated development of regions. The transformation of regional land use function is the inevitable result of rapid urbanization and one of the important characteristics of regional spatial function transformation and reconstruction. This study was based on the district and county scale and the dominant function of land use, and used synthetically index method, coupled coordination degree model, and geographically and temporally weighted regression model (GTWR). This paper analyzes the spatio-temporal evolution track and spatial equilibrium state of land use function transformation in the urban agglomeration around Poyang Lake under a long time series, divides the transition stage of each county and region, and reveals the driving mechanism of land use function transformation. The results show that: (1) From the perspective of temporal changes, the land use function index of the urban agglomeration around Poyang Lake increased from 0.20 to 0.55 during 2000-2020, with continuous optimization and improvement, but it was still at a medium and low level in general, showing staged characteristics and experiencing a development process of slow developm-rapid increase and slow growth. From the perspective of spatial distribution characteristics, the functional index gradually presents a spatial distribution pattern of high in the east and west, low in the east, showing a significant spatial difference. (2) The index of coordination degree of production-life -ecological function and production-life function continued to rise, while the other coupling degree and coordination degree index showed a trend of fluctuating development. The production-life function showed a low level and high coupling phenomenon from 2000 to 2010, and the life and ecological function lagged behind the development of production function from 2010 to 2015. The coupling coordination index showed a spatial distribution pattern of high in central and southwest, low in northeast and northwest, and the gap between regions and counties widened. The overall transformation is mainly low-quality, with the average number of districts and counties accounting for about 50%, but the number of districts and counties in the transition period and high-quality transformation has increased, and the quality of functional transformation has improved. The quality of land use function transformation in the central and western regions is obviously better than that in the northern and eastern regions. The high-quality transformation regions are mainly located along the Chang-jiu Economic Corridor and Xinyiping city cluster, while the eastern and northern regions are mostly low-quality transformation. (3) There are significant spatial differences in the driving effects of different influence factors. The positive driving effect of population density and urbanization level continued to increase, the negative driving effect of the proportion of secondary and tertiary industries increased, and the influence of per capita GDP, per capita fixed asset investment and per capita grain output tended to weaken. The Poyang Lake city cluster should implement differentiated development policies according to the transition stage of land use function of each district and county, make up for the development shortcomings of district and county, and enhance the coupling and coordination degree of functional systems. The research results can provide reference and decision-making basis for improving regional land use efficiency and promoting multi-functional cooperative development of land use.