In this research,15% Topik wettable powder(WP) was applied to investigate the control effects of Avena fatua L. and the influence of weed control on sunlight, nutrition and crop yield of winter wheat. The results showed that 15% Topik WP had good control effects on Avena fatua L.. The density and fresh control effects reached 97.27%～100.00% and 98.86%～100.00% respectively. The application of Topik significantly improved the light conditions in winter wheat fields and reduced the weeds absorption of nutriton and moisture，resulting in a significant acceleration of photosynthesis and prominent effects of yield enhancing.