Abstract BACKGROUND Naematelia aurantialba polysaccharide (NAPS) is widely exploited in the food and pharmaceutical industries because of its diverse biological activities. Although chemical elicitors have been reported to enhance polysaccharide production by edible mushrooms under submerged fermentation, their influence on NAPS biosynthesis remains unexplored. RESULTS We evaluated the effect of chemical agents on NAPS synthesis in 7.5 L fermenters. Supplementation with 0.50% (v/v) polyoxyethylene sorbitan monooleate (Tween 80) raised the NAPS yield to 17.32 ± 0.25 g L −1 , a 15.31% increase over the control and shortening the fermentation duration by 12 h. Fourier transform infrared spectroscopy confirmed that the NAPS‐T80 possessed the same backbone structure as the NAPS. Scanning electron microscopy revealed a smoother surface for NAPS with Tween 80 (NAPS‐T80), which also exhibited a marked enrichment in glucose and galactose residues and a molecular weight increase from 2.948 × 10 6 to 3.537 × 10 6 Da. Rheological analyses, antioxidant assays, and emulsification tests all indicated superior functionality for NAPS‐T80. Transcriptomic profiling showed that T80 significantly upregulated genes involved in nucleotide sugar formation and in the assembly of polysaccharide repeating units. CONCLUSION This study establishes an effective T80 supplementation strategy to enhance NAPS yield and functionality in submerged fermentation, and further elucidates its mode of action as a metabolic regulator. These findings offer a sustainable method for generating NAPS and lay the groundwork for utilizing surfactants to boost yields of edible and medicinal fungal polysaccharides. This approach shortens the fermentation duration by 12 h, substantially reducing energy consumption and operational costs, offering an environmentally friendly and economically viable strategy for industrial‐scale polysaccharide production. © 2026 Society of Chemical Industry.