In fried food systems, the absence of gluten in rice flour-based coating batters results in low viscosity and poor structural integrity, thereby constraining their application. In this study, sanxan gum was incorporated into a rice flour-based batter to compensate for the viscosity deficiency, construct a denser gel network, and improve batter handling properties and oil reduction. The hydration properties, pasting behaviour, rheological characteristics, water mobility, and quality attributes of the fried products were evaluated. Results showed that sanxan gum increased batter viscosity and pick-up in a concentration-dependent manner and restricted starch granule swelling through competitive hydration. LF-NMR revealed no significant changes in water mobility, indicating that the oil-reducing effect of sanxan gum did not rely on water-state modulation. At 0.6% addition, the crust oil content (21.33%) decreased, meat tenderness (25.11 N) and moisture content (56.19%) improved, and the crust exhibited a continuous and homogeneous gel network. At 0.8% addition, although the crust oil content (15.07%) was the lowest, the total oil content per piece (0.69 g) was equivalent to that at 0.6% (0.70 g) due to moisture dilution and excessive crust thickness, accompanied by deteriorated microstructure and no further improvement in meat tenderness (24.05 N). These results demonstrate that sanxan gum effectively improves the functionality of rice flour-based coating batters and the quality of fried products by increasing viscosity, restricting starch swelling, and forming a continuous gel network, whereas excessive addition introduces structural drawbacks. This work provides a scientific basis for the application of sanxan gum as a functional hydrocolloid in deep-fried batter-coated food formulations.