Abstract: Food security is related to social harmony and the people's sense of well-being, accessibility and security, and plays the role of a cornerstone in comprehensively advancing Chinese-style modernization and solidly promoting the process of common prosperity. On the premise of reinterpreting the connotation of food security, this article constructs a food security measurement system that coordinates the development of “food” security and “eating” security, and analyzes the main factors affecting food security through an obstacle model. On this basis, it further explores the impact of food security on common prosperity. The results show that China’ s level of food security has made a leap from moderately unbalanced to well-coordinated during the period 2013-2021; Cultivated land, agricultural technology level, fluctuation of grain yield, use of agricultural chemicals, and grain price index are the biggest obstacles affecting food security; The impact of food security on common prosperity is systematic, and it is necessary to coordinate the promotion of “food” security and “eating” security in order to help improve the level of common prosperity. Finally, the paper puts forward countermeasures and suggestions to ensure China’ s food security and promote the early realization of common prosperity of all people in the context of Chinese path to modernization.