Assessing and mapping cultural ecosystem services (CES) is becoming a research hotpot, however, studies on the CES of cultivated land (CESCL) face several bottleneck problems, such as the lack of an effective analytical method for integrating multi-source data and a unified research framework. In this study, the aesthetic and recreational supplies of cultivated land in the Yangtze River Delta (YRD) region in 2010, 2015, and 2020 were measured and mapped with the Maximum Entropy (MaxENT) model by integrating geographic information data and agricultural big data. Moreover, the demand and flow of CESCL were quantified and the supply–demand-flow relationships were analyzed to enhance the comprehensive understanding of CESCL. The results showed that: (1) The MaxENT model could precisely quantify the supply of CESCL in the YRD region with AUC values greater than 0.85; (2) Cultivated land with high aesthetic supply was found closely related to natural factors while cultivated land with high recreational supply was highly dependent on socio-economic factors; (3) The levels of aesthetic supply and recreation supply and the agglomeration effects of CESCL in the YRD region during the period 2010–2020 were presented slowly increase trends which were much lower than that of the demand and flow of CESCL; (4) From a supply–demand-flow perspective, the high supply of CESCL was mainly distributed in mountains, hills, and regions near water bodies, while the high demand for CESCL was found in areas with high levels of economic development and the movement of CESCL was strongly influenced by national attractions. This study explores the method of quantifying CESCL at a regional scale from a supply–demand-flow perspective, which provides a reference for both value mapping and policy formulation of CESCL, and lays a theoretical basis for the comprehensive utilization of cultivated land resources in the context of high-quality development.