To analyze the response of food security to the spatial and temporal evolution of cultivated land function in mountain cities, so as to promote their stable and sustainable development. With the help of GAZE, INVEST and GIS models, the functions of production, ecology, landscape recreation and social security of cultivated land in Chongqing Metropolitan Area were calculated the temporal and spatial evolution characteristics of each function of cultivated land were analyzed by Getis-Ord GI*， and the index of food security was expressed by the index related to the quantity of grain, and Pearson was used to judge the response relationship of food security to each function of cultivated land. The results show:1) From 2000 to 2020, the cultivated land in the study area decreased by 5 677.76 km2, with an average annual decrease of 283.9 km2. 2) From the perspective of the changes of cultivated land functional hotspots, the production and ecological functions of cultivated land showed a downward trend, with a large decrease of 14%~22% in the first decade and a decrease of 10% in the second decade. The social security function showed a trend of first declining and then slowly increasing. The overall increase trend of landscape recreation function was about 10%. 3) From 2000 to 2020, food security and cultivated land production, ecology and social security functions developed in coordinated development, but the disorderly expansion of cultivated land landscape recreation function had an adverse impact on food security. The above results suggest that in order to ensure the food security of the study area, it is necessary to strictly adhere to the “red line of cultivated land” and prevent excessive conversion of cultivated land. At the same time, it is also necessary to appropriately control the “non-agricultural” and “non-grain” functions such as cultivated land landscape recreation. On the premise of ensuring regional food security, the utilization rate of cultivated land in mountainous cities should be improved and the efficiency of cultivated land should be improved.