Abstract: Constructed wetlands are widely used in aquaculture tail water treatment due to their high efficiency, simple operation and low cost. However, antibiotics such as tetracycline in the tail water have a certain impact on the removal of conventional pollutants. In this study, ceramsite ( PCW ) and iron-carbon + ceramsite (CCW) based tidal flow-subsurface flow composite constructed wetlands were constructed. By adding 0.2mg/L tetracycline and iron-carbon fillers, the removal effect of conventional pollutants and microbial community structure in the start-up stage of constructed wetlands were studied. The influent and effluent concentrations of COD_Cr, TP, NH₄⁺-N and TN were measured and analyzed. It was found that the addition of 0.2mg/L tetracycline inhibited the removal of pollutants during the start-up period of constructed wetlands to a certain extent. In particular, the inhibition is more pronounced in primary systems. The average removal rates of COD_Cr, TP, NH₄⁺-N and TN decreased by 0.59%, 1.51%, 9.57% and 1.97%, respectively. The removal rate of CCW system was higher than that of PCW system. The average removal rates of COD_Cr, TP, NH₄⁺-N and TN in TC group increased by 5.81%, 2.47%, 0.91% and 1.02%, respectively. The addition of iron-carbon filler promoted the removal of conventional pollutants and the removal effect in the tetracycline system.