ZnO nanobelts are synthesized in high yield by a simple chemical vapor deposition method, at low temperature. And then Au nanoparticles are sputtered on the ZnO nanobelts. The effect on the photoluminescence of Au-ZnO composite nanobelts by surface plasmon is systematically investigated by the scanning electron microscopy, transmission electron microscopy and photoluminescence spectrum. The enhancement ratio by surface plasmon resonance and the almost completely suppressed defect emission for Au-ZnO composite nanobelts are observed, and the emission enhancement ratio η of Au-ZnO composite nanobelts reaches a maximal value of 85-fold. Additionally, the photoluminescence mechanism is proposed in terms of the scattering and absorption by Au nanoparticles, the Purcell enhancement factor, and the Ostwald ripening.