The grain industry is the foundation for ensuring the food security system and the important part of the Chinese-style modernization. How to promote the development of Chinese-style modern grain industry is significant to achieve national security and socialist modernization. Since the Chinese-style modern grain industry is the product of “Chinese elements” and “modern objectives”, this paper constructed the evaluation index of Chinese style modern grain industry system, and used the entropy weight coefficient method to evaluate the modernization level of grain industry. It also used the coefficient of variation and Theil index to analyze the regional differences of production and marketing. The results showed that China’s grain security guarantee ability was strong, and the development of grain industry needs to be improved. The construction of supporting facilities in the post-production process, industrial coordination and integration, and the intensity of scientific research investment were the main factors restricting the development of the grain industry. Promoting the development of the Chinese-style modern grain industry not only improved national food security but also optimized the industrial structure, assisting in the transformation and upgrading of the grain industry. This could help sustain and increase grain production efficiency. It also energized key players in the grain industry to promote coordinated industry development and facilitate effective linkage between production and sales regions, which could narrow regional disparities.