Abstract: In order to investigate the impact of rainfall events on the occurrence of runoff and the water quality and quantity of the influent and effluent in the multi-pond constructed wetland, the characteristics of water quality and quantity during the two rainfall events on August 25^th and September 6^th in 2017 were analyzed to explore the changes of water quality, water quantity and the purification performance. The results showed that: (1) The peak time of water inflow in the multi-pond constructed wetland lagged behind the peak of the rainfall and the turning point of the cumulative rainfall. The rain intensity had no significant effect on the water quantity of influent water of the multi-pond constructed wetland, while the cumulative rainfall affected the amount of runoff, and then significantly affected the amount of water inflow, resulting in a sharp increase in the hydraulic load rate with a maximum value of 2.45 m³/(m²·d). During the rain events, the rising water level in the multi-pond constructed wetland increased water depth and effective volume, the hydraulic residence time were approximately prolonged. (2) The characteristics of water quality of the influent water of the multi-pond constructed wetland had no regularity with the rainfall, but the pollutant mass loads of the influent were always greater than those during the non-rainfall period. This indicated that only using the peak control of concentration for the treatment of runoff pollution during the rainfall period was not sufficient, especially in areas with frequent rainfall during the rainy season. More attention should be paid to the impact of pollution load on the purification performance. (3) During the rainfall period, the multi-pond constructed wetland had a good interception performance on runoff pollution, and the removal efficiencies of TN and TP were in the range of 33.6%-88.7% and 25.2%-78.0%, respectively. The increase of hydraulic load rate in the influent increased the disturbance, resulting in higher pollutant concentrations of the effluent than influent pollutant concentrations in some units. However, the subsequent cascade units in the multi-pond constructed wetland composed of storage ponds, surface flow wetlands, ponds, ecological floating bed and stabilization pond contributed to the interception of pollutants and enhanced the impact resistance to rainfall runoff and the stability of purification performance of multi-pond constructed wetland.