Abstract: The central government has put forward a major strategy of "six stability" and "six guarantees." As a "western granary, " Sichuan Province has a critical strategic position in ensuring national food security. Based on the grey relational analysis model, the factors that have a significant influence on the grain yield were screened out, and the GM model was used to forecast the grain yield and consumption in Sichuan Province, to analyze the balance between supply and demand, and to study the situation of grain security in Sichuan Province. The results show that the most important factor influencing grain output in Sichuan Province is the sown area of grain, followed by grain output per unit area and the number of employees in the primary industry. The grain production forecast model shows that Sichuan’s grain production will show a slow upward trend from 2021 to 2025. The grain forecast model shows that the demand for rations, feed grains, seed grains, and industrial grains has declined slightly, and grain losses have increased year by year. The total grain demand has shown a periodical characteristic of slow decline. From the two dimensions of supply and demand, the food security of Sichuan Province during the "14 th Five-Year Plan" period is calculated to be 83.69% to 92.81%. There is a certain gap in production and demand, and the guarantee capacity is insufficient.