This study aims to identify low-cost and high-quality alternative materials to replace traditional substrates for straw mushroom (Volvariella volvacea) cultivation, thereby improving resource utilization efficiency, reducing cultivation costs, and increasing farmers’ income. Using Arundo donax as the experimental material, cultivation trials were conducted by incorporating it into the substrate at different mass ratios (0%, 20%, 40%, 50%, 60%, 80%, and 99%). The suitability of A. donax as a substrate alternative was evaluated through analyses of straw mushroom growth, economic traits, and nutritional composition. The results demonstrated that a substrate containing 60% A. donax was the most suitable alternative formulation. Under this treatment, mycelial growth (2.40-2.42 cm/d), cropping cycle (18-23 d), commercial traits (mushroom length 4.33-4.83 cm, single mushroom weight 8.79-10.21 g), fresh mushroom yield (535.16-550.42 g/tray), and biological conversion rate (7.64%-7.86%) did not differ significantly from those of the control. When the content of A. donax≥80%, the indexes decreased significantly. Meanwhile, the nutritional quality of straw mushrooms cultivated with this formulation was significantly improved. The protein content reached 29.83 g/100 g, while the contents of essential amino acids, umami amino acids, ash, and crude fiber were 9.43, 12.46, 9.00 and 5.5 g/100 g, respectively, all of which were significantly higher than those of the control, and the fat content (1.3 g/100 g) was lower than that of CK. It is concluded that A. donax could be used as a high-quality alternative raw material for V. volvacea cultivation matrix, and 60% A. donax+ 39% cottonseed hull+ 1% gypsum is the optimal formula. This formula takes into account the growth, yield and nutritional quality of V. volvacea, and could achieve the dual goals of efficient utilization of resources and cost reduction.