SummaryDeveloping salt‐free frozen‐cooked wheat noodles (FCNs) has a promising future, and how to eliminate the deficiency of the absence of salt is key to enhance its quality. In this study, based on the unique ‘gel‐forming in cold water and gel strength‐strengthening during heating’ properties, sanxan was used to improve the quality of salt‐free FCNs and the underlying mechanism was initially explored. TPA analysis, colour profile, thermal stability analysis, determination of free sulfhydryl and disulphide bonds contents, scanning electron microscopy observation, confocal laser scanning microscopy observation were carried out. The results showed that adding 1.2% sanxan could minimise the decrease in hardness, springiness, maximum tensile strength and tensile fracture distance, and the increase in adhesiveness of salt‐free FCNs during freeze–thaw treatments (FTs). The chrominance and thermal stability of salt‐free FCNs during FTs were also improved by adding 1.2% sanxan. Adding sanxan could strengthen the gluten network of salt‐free FCNs by weakening the recrystallisation of ice crystals, inhibiting the breakage of SS and enhancing the cross‐linkage degree and continuity of gluten network during FTs. The current study could develop a new preparation strategy of salt‐free convenient noodles and provide theoretical basis for expanding the novel application of sanxan in frozen foods.