The present invention relates to a composition for a non-pneumatic tire spoke. In particular, the non-pneumatic tire spoke prepared from the composition for a non-pneumatic tire spoke has excellent mechanical properties. A composition for a non-pneumatic tire spoke includes a thermoplastic polyester elastomer, a silane-based interfacial binder, and silica particles. The silica particles have an average particle diameter of 100 to 300 μm.