Abstract: This study aimed to investigate the spatiotemporal variations of grain-to-straw ratios in wheat and maize, and evaluate the carbon sequestration and emission reduction potential of comprehensive straw utilization. Meta-analysis was employed to examine the spatiotemporal variation patterns of grain-to-straw ratios in wheat and maize. Based on the straw production and comprehensive utilization data from different counties in Henan Province, we assessed the fertilizer substitution potential of straw incorporation and the carbon sequestration and emission reduction potential of comprehensive straw utilization. The grain-to-straw ratio of wheat and maize decreased by 0.14 and 0.06, respectively, every five years. For every 1 000 kg increase in yield per hectare, the grain-to-straw ratio decreased by 0.36 for wheat and 0.09 for maize. In Henan Province, the eastern region showed the highest grain-to-straw ratio for wheat (1.14), while the central and western regions had the lowest (1.00). For maize, the southern region had the highest grain-to-straw ratio (0.9), while the eastern and northern regions had the lowest (0.77). From 2021 to 2023, straw incorporation in Henan Province has returned 102.8×10⁴ t of nitrogen, 36.14×10⁴ t of phosphorus, and 367.87×10⁴ t of potassium to the soil, with an average annual carbon sequestration of 259.44×10⁴ t. The fertilizer, feed, and fuel utilization of straw was equivalent to reducing carbon emissions by 252.99×10⁴ t annually. The grain-to-straw ratios of wheat and maize continuously decreased with time progression and yield improvement. The comprehensive utilization of straw in recent years plays a crucial role in improving soil fertility and reducing carbon emissions. Therefore, continuously promoting the integrated utilization of straw is an important pathway to achieving green agricultural development and the goals of carbon peaking and carbon neutrality.