The invention belongs to the technical field of rainwater treatment devices, and relates to a device, which is used for settling a pollutant in rainwater entering a rainwater pipe and filtering and discharging the rainwater. A removing and reducing device for a non-point pollution source comprises a sand settling pond, a settling pond, a flow adjusting pond, a filtering pond and a treated water pond, wherein one side of the sand settling pond is connected with a water inlet pipe; the upper end of a side wall on the other side of the sand settling pond is communicated with the settling pond; moreover, multiple filtering membranes are arranged at the interior of the sand settling pond; the interior of the settling pond is provided with a bottom opening or a partition wall which has a certain distance to a bottom surface; multiple absorbent paper fixing accessories are formed on the partition wall or two side walls in a protrusion manner; the upper end of one side wall of the flow adjusting pond is communicated with the settling pond; the other side of the flow adjusting pond is connected with the bottom of the filtering pond; the filtering pond is provided with more than two filtering layers, and is communicated with a filtered water discharge pipe of the treated water pond; the treated water pond is used for storing filtered water passing through the filtering pond. By using the removing and reducing device for the non-point pollution source, which is provided by the invention, the blockage possibility is not only structurally reduced obviously, the backwash and the reverse transfer process of backwash water are automatically completed through the backwash water and compressed air, the removing and reducing device for the non-point pollution source but also can be used for a long time without carrying out maintenance.