The utility model provides a sewage treatment device for constructed wetlands, belonging to the field of sewage treatment. The sewage treatment device for the constructed wetlands comprises a box body composed of a waterproof outer wall as well as a filter unit and at least one purification unit which are located in the box body and sequentially connected, wherein a water inlet pipe which is provided for the inflow of sewage and connected with the filter unit and a water outlet pipe which is provided for the outflow of purified water and connected with the purification unit are arranged on the waterproof outer wall. The device provided by the utility model is capable of organically combining different wetland types and increasing the sewage treatment efficiency.