Objective As the largest grain sales area in China, the grain security issue of Guangdong Province occupies a special important position in the overall situation of national grain security. The study evaluates the risk of the grain supply chain in Guangdong Province and proposes control strategies for the risks.

Method Based on the data of National Bureau of Statistics from 2003 to 2021, we used SPSS to conduct factor analysis and constructed a risk assessment index system of grain supply chain from the production end, including 12 indicators such as the area affected by natural disasters, the number of environmental emergencies and the consumer price index for grain in Guangdong Province. By using Stata for entropy weight method - TOPSIS, the sample data were analyzed for grain supply chain risk assessment, and Python was used for gray relation analysis to analyze the causes of changes.

Result The results of empirical analysis show that the risk of the grain supply chain in Guangdong Province can be summarized as three phases: the relatively higher risk phase (2003-2007), with a risk fit of 0.62 in 2004, reaching the peak in the past 20 years; the risk fluctuation phase (2008-2012), in which the risk of the grain supply chain declined compared with the previous phase, undulating up and down compared with the average level of risk; and the risk stabilization phase (2013-2021), in which the risk fit was between 0.3 and 0.4, maintaining around the average level.

Conclusion As a whole, the risk of the grain supply chain in Guangdong Province has been on a downward trend since 2003; the external risks are relatively low, and it can effectively safeguard the external supply of grain, but the grain production and reserves are insufficient; the internal supply risks are still high, among which the grain production, the risk-resistant capacity of grain enterprises and the consumer price index for grains are the main factors affecting the risk of the grain supply chain, with gray relations of 0.831, 0.824 and 0.805, respectively. In order to improve the self-sufficiency rate of grain in Guangdong Province and reduce the risk of the grain supply chain, four strategies for controlling the risk of the grain supply chain are proposed: improving the conditions of grain production, transforming the management mindsets of grain enterprises, optimizing the grain logistics system, and broadening the channels of grain imports.