In order to investigate the feasibility of pre-treatment of drinking water treatment plant by the constructed wetland and provide the operation parameters for a full scale constructed wetland to improve the quality of raw water. The constructed wetland series process was used to pre-treat influent water of drinking water treatment plant based on raw water of the Song hua jiang River. The results showed that when the influent flux was 1m3/d, the average removal rates of Turbidity, COD, TN and NH4+-N in the constructed wetland system were 94.27%, 56.77%, 2.37% and 55.65% , respectively. The wetland system has high treatment effect and run stably in the pretreatment process of the raw water. This system could lighten the load of the conventional water treatment processes effectively.