Photocatalytic hydrogen (H2) production from ammonia borane (AB) hydrolysis is a promising pathway for generating clean energy. Constructing appropriate heterojunctions represents an efficient strategy for enhancing the catalytic activity. Herein, a Ru0.7Cu0.3/W18O49 Schottky junction is successfully designed, which greatly enhances transfer and separation of photogenerated charge carriers. Moreover, the metallic Ru0.7Cu0.3 exhibits localized surface plasmon resonance (LSPR), which greatly enhances the light harvesting capability. As expected, the optimized Ru0.7Cu0.3/W18O49 photocatalyst exhibits a superior visible-light-driven H2 generation yield of 880 mL min−1 g−1 with excellent stability. The turnover frequency (TOF) value of Ru0.7Cu0.3/W18O49 was found to be 1.44 times higher under visible light irradiation compared to the dark condition, achieving 133.1 min−1. The present study establishes a pioneering approach for the systematic design of highly efficient and durable heterostructure catalysts.