Abstract: To alleviate the tight constraints on land resources in South China and lay a solid foundation for regional food security, based on the industrial statistics and targeted research data of Guangdong Province, this paper systematically examines the development characteristics and optimization paths of the three major dry grains - sweet potatoes, corn, and potatoes from 2015 to 2024. The research findings are as follows, the scale of the industry has steadily expanded, but the trends of different categories have significantly diverged. The planting area, total output, and yield per unit area of dry grains have increased from 34.04×10⁴ hm², 157.66×10⁴ t, and 4 631.6 kg/hm² in 2015 to 35.49×10⁴ hm², 177.30×10⁴ t, and 4 996.2 kg/hm² in 2024 respectively. Among them, the planting area, output, and per unit yield of sweet potatoes have simultaneously improved, and the development is the most stable; the yield of corn has shown a prominent increase, presenting a feature of quantity and efficiency coordination; potatoes have been under pressure from insufficient policy supply and relatively low comparative benefits, and their planting area and output have continued to decline, which is the main bottleneck restricting balanced development. The production spatial clustering pattern of the three major dry grain industries in Guangdong is clear. The main production areas of sweet potatoes are concentrated in the western and eastern regions of Guangdong Province, which account for about 65% of the total in Guangdong. Corn is centered in the western region of Guangdong Province, and potatoes are mainly concentrated in the western part of the Pearl River Delta. The shortcomings of the full industrial chain collaboration remain prominent, manifested as increased risks of price fluctuations in the market, insufficient processing, storage and transportation capabilities, weak commercialization of scientific and technological achievements, and low levels of organization and socialization services of business entities. To address this, a implementation path centered on monitoring and early warning of production and sales big data, dual-chain collaboration of processing, storage and transportation and brand, collaborative innovation in green production of seed industry and agricultural machinery, and multi-departmental provincial-level linkage guarantee is proposed, with the aim of optimizing resource allocation, enhancing regional food security capacity, and providing empirical evidence for the improvement and efficiency enhancement of the South China dry grain industry.