For its rapid growth, high yield, and broad adaptability, Arundo donax is widely used in various applications, yielding considerable economic and ecological benefits. However, widespread cultivation is challenging because A. donax can only be propagated asexually. In this study, a tissue culture method was developed using the clustered bud proliferation pathway. The explant type, disinfection method, induction medium, proliferation medium, and rooting medium were optimized to efficiently harvest high-quality A. donax seedlings. Using axillary buds with whole cane fragments as the most suitable explants, they were first sterilized with 75% alcohol for 30 s and then disinfected with 0.1% mercuric chloride for 5 min. 97.8% of explants could successfully form clustered buds on Murashige and Skoog (MS) medium supplemented with 5.0 mg/L 6-benzylaminopurine (6-BA) and 1.0 mg/L 3-indolebutyric acid (IBA). Each individual bud achieved efficient propagation with a proliferation coefficient as high as 33.3 on MS medium supplemented with 4.0 mg/L 6-BA and 1.0 mg/L IBA. In addition, all buds were capable of rooting on 1/2 MS medium supplemented with 0.5 mg/L 1-naphthaleneacetic acid (NAA). The resultant rooted seedlings survived and developed into plantlets, averaging 44.84 cm in height and 2.54 mm in thickness, following a 30-day acclimation period. This protocol provides a robust foundation for the large-scale, high-quality propagation of A. donax, supporting its broader application in ecological restoration and bioresource industries.