China attaches great importance to food security. With the strong promotion of the government, China’s grain output has achieved a great feat from "shortage" to "surplus in bumper years" and then to "rising steadily", achieving a record "increase for the tenth consecutive year". From the current balance of food supply and demand in China, the food security situation can be guaranteed on the whole. However, if we analyze the food security in China from the perspective of agricultural sustainable development strategy, there are some difficulties, such as the reduction of cultivated land area, the decline of cultivated land quality, the fragility of agricultural ecological environment, and the transformation of residents’ consumption structure. This paper analyzes the difficulties faced by the development of food security in China under the strategy of sustainable agricultural development, and puts forward that to implement the strategy of sustainable agricultural development, it is necessary to realize the coordinated development of food security, science and technology, ecological environment, resources and society.