With the growing demand for healthy diets among consumers and the ongoing implementation of policies to reduce and limit sugar intake in China, the development of novel sweeteners that combine a low glycemic index (GI) with excellent sensory qualities has become a hot topic in food industry research. In this study, sugarcane molasses was used as the raw material. After clarification and filtration via lime precipitation, followed by clarification and desalination using mixed resins, it was blended with sodium caseinate (NaCas) and gum arabic (GA). Low-GI hollow sugar was then prepared via spray drying. The product characteristics of this hollow sugar were systematically verified through characterization of appearance, structure, and composition, combined with in vitro hypoglycemic experiments and sensory evaluation. The results indicate that the prepared hollow sugar granules have a particle size of approximately 20 μm, with a total sugar content of 30.38%–35.71%, a polyphenol content of 10.17~12.00 mg GAE/g, and a flavonoid content of 6.82~7.34 mg RE/g; In vitro experiments showed that the IC₅₀ values for α-glucosidase and α-amylase were 22.34 mg/mL and 15.42 mg/mL, respectively. With a GI value below 22.3, the product is classified as a low-GI food. Its low-GI properties stem from the inhibitory effects of polyphenols and flavonoids on digestive enzymes, while the hollow structure reduces the actual intake of sugar. This study provides a reference for the high-value utilization of sugarcane molasses and the development of low-GI sweeteners.