The invention relates to a sewage treatment device by combining a tidal current artificial marsh and a soil percolation system as well as a method thereof, the sewage treatment device comprises a sewage equalizing tank, a tide current artificial marsh, a collecting pit and the soil percolation system, two layer of gravel filters are horizontally filled in the tidal current artificial marsh, the inlet pipe is positioned at top of one end, the outlet pipe is positioned at bottom of the other end; a soil filling material with different particle sizes are filled in the soil percolation system, the water pipe is paved at 30cm of the system depth, and the outlet pipe is paved at the bottom. The invention also relates to a sewage treatment method by combining the tidal current artificial marsh and soil percolation system. The device has the characteristics of high removal efficiency of the pollutant and stable operation effect, and is especially suitable for removing pollutants such as nitrogen, and can be used for treating municipal sewage as well as centralized and distributed life sewage in rural places.