NOVELTY - A bioactivity percolation domestic sewage treating device comprises water inlet part, percolating part and water outlet part. The water inlet part has water inlet, water inlet pipe, water inlet grid, and water inlet precipitating grid. The water inlet is arranged on one side of water inlet precipitating grid. The top of percolation grid is provided with top cover and the inside is provided with 2 gratings which divide percolating grid into 3 layers from top to bottom. The 3 layers are absorbing filter material layer, bioactivity filter material layer and oxidizing filter material layer.    USE - Bioactivity percolation domestic sewage treating device.    ADVANTAGE - The device uses land percolation technique and is suitable for each kind of sewage treating department and user.    DETAILED DESCRIPTION - The bioactivity percolation domestic sewage treating device comprises water inlet part, percolating part and water outlet part. The water inlet part consists of water inlet, water inlet pipe, water inlet grid, and water inlet precipitating grid. The water inlet is arranged on one side of water inlet precipitating grid equipped with water inlet of water inlet precipitating grid. The water inlet grid is adjacent with water inlet precipitating grid. The percolating part equipped between water inlet part and water outlet part has percolating grid and top cover. The top of percolation grid is provided with top cover and the inside is provided with 2 gratings which divide percolating grid into 3 layers from top to bottom. The 3 layers are absorbing filter material layer, bioactivity filter material layer and oxidizing filter material layer. The one side of bottom of oxidation filter material layer is provided with water outlet of percolating grid. The water outlet part has water outlet, water outlet grid and water outlet precipitating grid. The water outlet is arranged on one side of water outlet grid. The water outlet pipe is inserted in water outlet grid, and water outlet of precipitating grid is mounted on water outlet precipitating grid. The water outlet gird is adjacent with water outlet precipitating grid, and water outlet of precipitating grid is equipped between water outlet grid and water outlet precipitating grid.