Abstract: Cultivated land is mostly used to raise crops, and thereby the evaluation of cultivated land use can be expected from the perspective of crop planting, in order to ensure the subsequent refined research of cultivated land use and food security. Taking Baiquan, Keshan and Yi'an county as the research areas, this study aims to extract the spatial distribution information of cultivated land use on major food crops, including maize, soybean, and rice, during the implementation period of national planting structure adjustment policy from 2016 to 2019. Sentinel-2 remote sensing data and random forest classification were used in this study. ArcGIS 10.2 software was selected to achieve the annual crop classification, ranging from dividing various cultivated land into regions, then to counting into the vector map spots of cultivated land. The spatial distribution map of cultivated land use on main grain crops from 2016 to 2019 was obtained with the plot as the statistical unit. Standard deviation ellipse and main center models were used to analyze the quantity and spatial differentiation characteristics of cultivated land use. In addition, the spatial exploratory analysis method was used to explore the spatial correlation of cultivated land use structure in 48 towns. The results show that: 1) During the research period, there was obvious change characteristics of "scissors difference" occurred in the planting area of soybean and maize, whereas, the planting area of rice basically remained stable, indicating the dominated implementation effect of maize reduction policy, while soybean and maize became the main food crops. The proportion of soybean planting in the total cultivated areas increased from 7.18% to 44.94%, whereas the maize planting decreased from 88.19% to less than 50%, and the rice planting remained at about 5% of the total cultivated areas. 2) The spatial distribution of cultivated land use demonstrated a typical dynamic pattern of "from northwest to southeast". During the study period, the driving force of soybean distribution was strong, whereas the spatial distribution of maize was relatively constant. The main center of cultivated land use on soybean and maize was in the middle east of the study area. The center of land use on soybean crop shifted 27.17 km clockwise from east to south, while the center of land use on maize crop moved 25.52 km anticlockwise from west to south, possibly due to the policy implementation of planting structure adjustment from 2016 to 2019. 3) There was strong positive or negative spatial correlation among the structure variation of cultivated land use on main grain crops in the study areas. The area type of positive correlation mostly occurred in the form of cluster, indicating strong clustering and remarkable regional consistency. In the type of negative correlation, there was no obvious aggregation area, showing small number and sporadic distribution. The findings reveal the quantity and distribution features of major grain crops, particularly on soybean, maize, and rice, indicating the comprehensive situation of cultivated land utilization in the implementation period of planting structure adjustment policy in the study area. This study can provide a promising insightful reference for the regional planting structure adjustment and urban food security in the cultivated land use.