The invention relates to a river bank type infiltration system and a method with a water body remediation function. The river tank type infiltration system comprises a water diversion facility with aforebay, wherein multiple infiltration tanks stepwise arranged along two sides of a river bank are arranged at a downstream of the water diversion facility; a trash holding meshes are arranged at upstreams of inlets of the infiltration tanks; an intake gate and a discharge gate are arranged at an inlet part and an outlet part of each filter tank; each discharge gate is connected with a discharge tank communicated with a river channel; each infiltration tank is sequentially provided with a porous water retaining breast wall, a front permeable section, a multi-stage infiltration section, a rearpermeable section and a porous plate from the inlet to the outlet. The infiltration system is located beside at the river bank or a lake bank, is combined with an existing water conservancy project and is joined with a shoreside terrain, so that the normal operation of an original water conservancy project cannot be affected, and the water quality of the downstream river channel is maintained andimproved at the same time; the infiltration system can be also combined with river bank remediation, and green plants are planted at the upper part, so that the environment is beautified. The system has low cost, and is suitable for advanced nitrogen and phosphorus removal of seriously polluted urban rivers and sewage treatment plant tail water, and control of agricultural non-point source pollution.