The utility model discloses an urban rainwater collecting ecological filter. The urban rainwater collecting ecological filter is characterized in that a filtering dielectric layer is arranged in a filter body, a transition dielectric layer for supporting the filtering dielectric layer is arranged below the filtering dielectric layer, a compost covering layer is covered on the upper surface of the filtering dielectric layer, and plants are planted on the compost covering layer; the lower part of the filter body is provided with a drain pipe for draining treated rainwater, and the upper part of the filter body is provided with an overflow pipe which enables untreated rainwater to overflow; and a rainwater detention region is arranged above the filtering dielectric layer in the filter body. The urban rainwater collecting ecological filter has the advantages of being reasonable in structure, being capable of treating and collecting rainwater, providing lots of high-quality water sources selectively used for cities, and simultaneously solving the environmental problem of cities caused by rainstorms. Viewed from ecology, the rainwater collecting ecological filter can be used for serving as or replacing conventional urban greening very well and has the characteristics of environment friendliness and strong compatibility.