A Comprehensive Evaluation of Food Security in China and Its Obstacle Factors

China's food security has attracted global attention as the various drivers of its instability and uncertainty have intensified. This study developed a new framework for food security evaluation in China by analyzing its availability, distribution, utilization, vulnerability, sustainability, and regulation. The entropy weight method (EWM) and the matter-element extension model (MEEM) were combined to examine China's food security status between 2001 and 2020. Additionally, an obstacle degree model (ODM) was used to investigate the key factors functioning as obstacles to food security. The results show that China's overall food security improved greatly but experienced a slight downward trend in 2003. The main obstacles initially entailed grain distribution but then spread to vulnerability- and sustainability-related issues. Ultimately, the key factors restricting China's food security were the amount of fertilizer application per unit sown area (AFA) and the grain self-sufficiency rate (GSR). The next 40 years could be the most critical period for ensuring China's food security, which incorporates demographic, climate change, and resource shortage factors. China appears to be implementing its national strategies through sustainable farmland use and agricultural technology innovation to facilitate the high-quality development of its grain industries and strengthen its food security. This study provides an overall picture of China's food security and can serve as a reference for those concerned with China's future national security.