<p>More than 85% of China's sugar production originates from cane sugar processing, which requires substantial freshwater resources and generates significant wastewater. In order to quantitatively assess the impact of wastewater discharge from cane sugar industry on water resources, this study applied the grey water footprint (GWF) theory to evaluate the GWF of China's cane sugar industry. The calculation results show that the GWF of cane sugar based on the national discharge standard of water pollutants for sugar industry and Guangxi Zhuang Autonomous Region discharge standard of water pollutants for cane sugar industry was 714 m³/t and 80 m³/t, respectively. However, over 75% of sugar mills exhibited an actual GWF ≤ 28.6 m³/t. Regionally, the average cane sugar GWF in Guangxi was 12.9 m³/t; compared to 22.3 m³/t in Guangdong and 24.4 m³/t in Yunnan provinces. From 2013 to 2022, the average GWF per ton of sugar decreased significantly from 276.5 to 16.4 m³/t, with the corresponding total GWF decreasing from 42.88 × 10⁸ to 2.20 × 10⁸ m³, respectively. This study highlights the need to revise wastewater discharge standards for the cane sugar industry, aligning them with current operational realities. Such revisions are crucial for effectively regulating discharges, incentivizing technological upgrades, enhancing water conservation and recycling, reducing wastewater generation at source, improving pollution control, and ultimately mitigating the industry's GWF and impact on the water environment.</p>