Abstract: This study aims to explore the spatiotemporal evolution of the production-living-ecological functions. Their influencing factors were also evaluated to clarify the relationship among the production-living-ecological functions at multiple scales. The study area was taken as the urban agglomeration in the Middle Reaches of the Yangtze River. The root mean square error (RMSE) and Bayesian network (BN) were used to reveal the scale response to the relationship among the production-living-ecological functions trade-offs and influencing factors. The influencing mechanisms were obtained in the study area from 2010 to 2020. The results showed that: 1) The increasing trend was found in the production and living functions of the urban agglomeration. The hot spots of production function were located along the development axis of the river. While the hot spots of living function were distributed in the three major metropolitan areas. The overall ecological function shared no significant change, whereas the spatial distribution of the pattern remained unchanged. 2) The trade-off relationship showed that the production-living-ecological functions shared the variable and complex interactions at multiple scales. The production-living-ecological functions trade-offs were characterized by the ‘V’-shaped evolution or ‘falling-rising-falling’ pattern with the expanding of the study scale. Among them, the township scale was the weakest and the most spatial autocorrelation between the production-living-ecological functions trade-offs. The priority scale of territorial space was selected as the township, which was one type of multi-provincial administrative unit. 3) More than 30% of high values were found in the production-living-ecological functions trade-offs at multi-scale. There was a relatively low synergy of the production-living-ecological functions. According to the human-land relationship and scale thinking, the influencing factors were determined, including natural resource allocation, socioeconomic demand, location, and policy orientation. There was a great variation in the dominant factors of the trade-off relationship at multiple scales. Natural resources played a significant role at the micro scale. While the socioeconomic and locational factors were attributed to the strong trade-off relationship of the production-living-ecological functions at the administrative unit scale. The influencing factors varied significantly at different scales. The socioeconomic factors were also dominated at the full scale. Subsequently, the optimal regulation can be realized on the territorial spatial management and control at various levels. The findings can provide theoretical support to promote sustainable development in this region.