The utility model belongs to a sewage-treatment device, which especially relates to a device of treating sewage via soil; the device includes a drainage pipe 1 and a collection pipe 2; the utility model is characterized in that a collecting well 4 is also provided, the drainage pipe 1 is arranged in parallel, the distance between two adjacent drainage pipes 1 is 5m to 10m; the collection pipe 2 is installed at one end of the drainage pipe 1, the collection pipe 2 is connected with the drainage pipe 1 via a tee, and the water outlet of the collection pipe 2 is connected with the collecting well 4. When the water is accumulated to certain height in the collecting well 4, a water pump will be started to draw the secondary water for discharging or reutilization. The sewage-treatment device acquires fine sewage treatment effect through soil physical and biochemical process and cropper absorption process.