Cultivated land serves production, ecological and cultural functions. It is of great significance to scientifically evaluate the multifunctionality of cultivated land and reveal the evolution of its trade-off/synergy relationships and driving mechanisms, which is conducive to enhancing the comprehensive benefits of cultivated land and promoting the coordinated development of multiple functions. This study took the suburban area of Nanchang City as the research area. Based on multi-source data such as soil, topography, meteorology, remote sensing, and social economy from 2012 and 2022, it comprehensively used the coupling coordination degree model, spatial autocorrelation, and spatial Durbin model to systematically analyze the driving mechanism of the spatiotemporal evolution of trade-offs/synergies among multiple functions of cultivated land. The results showed that: The comprehensive level of multiple functions of cultivated land in the suburban area of Nanchang City was slightly improved, presenting a spatial differentiation characteristic of “strengthening in the center-weakening at the periphery”. The region generally maintained a synergistic state, but the coupling coordination degree was slightly decreased, and the spatial pattern showed a stepped differentiation of “rising in the west and falling in the east”. Factors such as altitude, agricultural population, per-capita GDP, the proportion of the secondary industry, and agricultural machinery power had a direct impact on the local coordination degree. Factors such as agricultural labor force, per-capita GDP, urban disposable income, urbanization rate, the proportion of the secondary industry, and agricultural machinery power had significant spatial spillover effects on neighboring regions, affecting the coordinated development of neighboring regions. The research results provide a basis for formulating differentiated and diversified utilization strategies for suburban cultivated land, and promote the synergy of multiple functions of cultivated land and overall regional coordination.