Abstract: To enhance the quality of frozen white amur carp surimi and promote the development and utilization of high-quality surimi products, this study prepared a composite antifreeze agent using soybean oligosaccharides and konjac glucomannan (Konjac Glucomannan, KGM) as raw materials, systematically investigating its cryoprotective effects on white amur carp surimi. A single-factor experiment was conducted, with myofibrillar protein (Myofibrillar Protein, MP) content as the indicator, to optimize the ratio of soybean oligosaccharides and KGM in the composite antifreeze agent. The MP content, total sulfhydryl content, endogenous fluorescence spectra, SDS-PAGE electrophoretic patterns, as well as surimi gel strength, water-holding capacity, whiteness, and microscopic structure were measured to analyze the cryoprotective mechanism of the composite antifreeze agent on white amur carp surimi and its gel system. The results showed that the optimal ratio of the composite antifreeze agent determined by the single-factor experiment was 4% soybean oligosaccharides+0.3% KGM. By measuring the MP content, total sulfhydryl content, endogenous fluorescence spectra, SDS-PAGE electrophoretic patterns, as well as surimi gel strength, water-holding capacity, whiteness, and microscopic structure, the cryoprotective mechanism of the composite antifreeze agent on white amur carp surimi and its gel system was further analyzed. The study revealed that after 90 days of frozen storage at −20 ℃, compared to the blank group, the 4% soybean oligosaccharides+0.3% KGM composite antifreeze agent effectively mitigated the decline in MP content during frozen storage, significantly inhibited protein denaturation and degradation, and maintained favorable gel properties, color, and microscopic structure, effectively preserving gel quality and demonstrating excellent cryoprotective effects on white amur carp surimi. This composite antifreeze agent combines the dual advantages of green safety and efficient protection, making it a promising candidate for development as a novel surimi antifreeze agent and industrial application.