The invention relates to the field of environmental engineering, especially to a sewage treatment plant for treatment of domestic sewage and a sewage treatment technology thereof. According to the technical scheme, the domestic sewage treatment plant is characterized by successively comprising a first-stage aeration area, a first-stage vertical-flow constructed wetland area, a second-stage aeration area, a second-stage vertical-flow tidal-flow combined constructed wetland area and an effluent area in the flowing order of sewage. The sewage treatment technology comprises the following steps: 1,COD concentration of sewage is 150-500 mg/L; and 2, sewage successively enters the first-stage aeration area, the first-stage vertical-flow constructed wetland area, the second-stage aeration area, the second-stage vertical-flow tidal-flow combined constructed wetland area and the effluent area and is finally discharged through a pump. Through the above scheme, the invention brings forward a novel sewage treatment device which effectively removes organic matter in sewage and can change ammonia nitrogen into nitrate nitrogen and also can make good use of advantages of wetland areas and a sewage treatment technology thereof.