The paper aims to investigate the effect of exogenous glycine betaine on seed germination, especially the respiration during germination, under low temperature stress. This study used the Sorghum bicolor× S. sudanense variety ‘Youmu 2’ as the experimental material to investigate the effects of glycine betaine (GB) on respiratory electron transfer during seed germination and seedling growth under low temperature stress. The results indicated that: 15 mmol/L GB treatment significantly increased the germination potential, germination index, germination rate, shoot length, and root length of Sorghum bicolor× S. sudanense seeds during low-temperature germination. It also significantly increased the total respiration rate, COX respiration rate, AOX respiration rate, and the proportion of COX in the total respiration of Sorghum bicolor× S. sudanense seeds during low-temperature germination. However, it had no significant effect on the proportion of AOX in the total respiration. Its effect on the proportion of COX respiration and AOX respiration in total respiration gradually decreased with increasing temperature, significantly increasing the SOD activity, POD activity, and CAT activity of Sorghum bicolor× S. sudanense seeds during low-temperature germination, and significantly reducing their H2O2 content. It significantly improved the SOD activity, POD activity, and CAT activity of Sorghum bicolor× S. sudanense seeds during low-temperature germination, and significantly reducing their H2O2 content. The germination rate, germination potential, germination index, shoot length, and root length of Sorghum bicolor× S. sudanense seeds under low temperature germination with 15 mmol/L GB treatment showed a highly significant or significant positive correlation with AOX respiration rate, COX respiration rate, and total respiration rate, and a highly significant or significant negative correlation with CAT activity, SOD activity, POD activity, and H2O2 content. The plant height, root length, stem length, and leaf length of Sorghum bicolor× S. sudanense seedlings grown at low temperatures under 15 mmol/L GB treatment showed a highly significant or significant positive correlation with total fresh mass, aboveground fresh mass, and underground fresh mass, and a highly significant or significant negative correlation with H2O2 content. Therefore, GB could increase the respiration rate of COX and AOX in seeds, enhance the antioxidant enzyme activity of seeds and seedlings, reduce the production of reactive oxygen species, effectively alleviate the oxidative damage to seeds and seedlings under low temperature stress, promote the germination of Sorghum bicolor× S. sudanense seeds and the growth and development of its seedlings under low temperature stress.