Youmian Yuyu (fish-shaped naked oat noodles) is a distinctive traditional naked oat staple food in northern China, which suffers from prominent quality deterioration during frozen storage. The raw and cooked samples were received as research objects and made four freezing treatments: conventional freezing at –18 ℃, quick freezing at –40 ℃, ultra-low temperature quick freezing at –80 ℃, and liquid nitrogen quick freezing. The effects of different freezing methods on the quality of Youmian Yuyu were comprehensively compared by determining the Pasting properties, relative starch crystallinity, and protein secondary structure of raw and cooked Youmian Yuyu. After 56 d of frozen storage, –40 ℃ quick freezing achieved significantly better quality maintenance, with a 33.84% setback increase, 21.89% relative crystallinity, 22.57% free sulfhydryl reduction for cooked samples, and 8.66% setback decrease, 10.11% α-helix reduction for raw samples. For the –40 ℃ treated groups, the magnitude of changes in peak viscosity, setback value, relative starch crystallinity, and degree of short-range order were significantly lower than those of the –18 ℃ conventional freezing groups, with more stable protein secondary structure and well-maintained gel network structure. These results demonstrate that –40 ℃ quick freezing pretreatment can significantly delay the quality deterioration of both raw and cooked Youmian Yuyu, performing significantly better than –18 ℃ frozen storage, with no substantial difference compared to –80 ℃ ultra-low temperature quick-freezing and liquid nitrogen quick-freezing. –40 ℃ quick freezing effectively inhibits starch retrogradation and protects protein structure of Youmian Yuyu. These results provide a theoretical basis and technical reference for long shelf-life preservation and industrial large-scale production of this traditional staple food.